diff --git a/Authentication.md b/Authentication.md
index 356686a..0f21f4d 100644
--- a/Authentication.md
+++ b/Authentication.md
@@ -1,10 +1,11 @@
 ## Autentication
-Farmmaps uses OpenID: https://auth0.com/docs/protocols/oidc/openid-connect-discovery  
+Farmmaps uses OpenID-connect: https://openid.net/connect/
 
 It is recommended to use a library to facilitate the authentication.  
 To get the openid configuration call the following url: https://accounts.farmmaps.awtest.nl/.well-known/openid-configuration 
 
 The user could also use the openid-configuration to handle authentication by themselves.  
+https://identitymodel.readthedocs.io/en/latest/native/overview.html
 
 The token received needs to be used in the request header.
 >'Authorization': 'bearer {token}'
diff --git a/Create-Cropfield.md b/Create-Cropfield.md
index 5db1287..7481cb4 100644
--- a/Create-Cropfield.md
+++ b/Create-Cropfield.md
@@ -25,7 +25,7 @@ GET /api/v1/folders/my_drive
 * Create a 'FOLDER' item as a child of the 'my_drive' item.  
 >Request
 ```javascript
-POST /api/v1/item
+POST /api/v1/items
 {
   "parentCode": "{my_drive_code}",
   "itemType": "FOLDER",
@@ -64,15 +64,19 @@ Response 401 Not authenticated
 Response 403 No WRITE permissions in parent item  
 Response 404 Parent Item not found  
 
-* Create a 'vnd.farmmaps.itemtype.cropfield' item as a child of the 'FOLDER' item.
+* Create a 'vnd.farmmaps.itemtype.cropfield' item as a child of the 'FOLDER' item.  
+Needs to contain dataDate and dataEndDate to specify cropfield season.  
+dataDate needs to be before dataEndDate and cannot be the same day.  
+ 
 > Request
 ```javascript
-POST /api/v1/item
+POST /api/v1/items
 {
     "parentCode": "{FOLDER_item_code}",
     "itemType": "vnd.farmmaps.itemtype.cropfield",
     "name": "cropfield for VRA",
-    "dataDate": "2019-11-25",
+    "dataDate": "2019-1-18T10:16:21.455Z",
+    "dataEndDate": "2019-12-18T10:16:21.455Z",
     "data": {},
     "geometry": {"type":"Polygon","coordinates":[[[6.09942873984307,53.070025028087],[6.09992507404607,53.0705617890585],[6.10036959220086,53.0710679529031],[6.10065149010421,53.0714062774307],[6.10087493644271,53.0716712354474],[6.10091082982487,53.0716936039203],[6.10165087441291,53.0712041549161],[6.10204994718318,53.0709349338005],[6.10263143118855,53.0705789370018],[6.10311578125011,53.0702657538294],[6.10331686552072,53.0701314102389],[6.103326530575,53.070119463569],[6.10309137950343,53.0699829669055],[6.10184241586523,53.0692902201371],[6.10168497998891,53.0691984306747],[6.10092987659869,53.0694894453514],[6.09942873984307,53.070025028087]]]}
 }
diff --git a/Polling-task-status.md b/Polling-task-status.md
new file mode 100644
index 0000000..d5d1622
--- /dev/null
+++ b/Polling-task-status.md
@@ -0,0 +1,55 @@
+## Polling task status
+
+When a task is executed with the task API your retrieve a code.  
+This code can be used to poll the status of an item task execution.  
+
+The response 'message' field can contain a string message based on the context.  
+
+#### Get a list task of status for a given item
+> Request
+```javascript
+GET /api/v1/items/{code}/tasks
+```
+
+> Response 200 OK
+```javascript
+[
+{
+  "taskType": "string",
+  "code": "string",
+  "message": "string",
+  "state": "Error, Ok, Scheduled, Processing",
+  "started": "2020-03-20T11:13:20.568Z",
+  "finished": "2020-03-20T11:13:20.568Z"
+},
+{
+  "taskType": "string",
+  "code": "string",
+  "state": "Error, Ok, Scheduled, Processing",
+}
+]
+```  
+Response 401 Not authenticated  
+Response 403 No READ permissions in parent item  
+Response 404 Parent Item not found 
+
+#### Get the status of a task for a given item and item task code
+> Request
+```javascript
+GET /api/v1/items/{code}/tasks/{itemTaskCode}
+```
+
+> Response 200 OK
+```javascript
+{
+  "taskType": "string",
+  "code": "string",
+  "message": "string",
+  "state": "Error, Ok, Scheduled, Processing",
+  "started": "2020-03-20T11:13:20.568Z",
+  "finished": "2020-03-20T11:13:20.568Z"
+}
+```  
+Response 401 Not authenticated  
+Response 403 No READ permissions in parent item  
+Response 404 Parent Item not found 
\ No newline at end of file
diff --git a/Upload-Data.md b/Upload-Data.md
index 701a689..0b256f6 100644
--- a/Upload-Data.md
+++ b/Upload-Data.md
@@ -2,6 +2,10 @@
 If the user wants to upload custom data (lutum/ec) they can use the FarmMaps file API.  
 The API is based on the google drive API.  
 
+C# explanation:   
+https://developers.google.com/api-client-library/dotnet/guide/media_upload  
+https://developers.google.com/drive/api/v3/manage-uploads#resumable
+
 * Start request
 
 > Request
diff --git a/VRANbs-API.md b/VRANbs-API.md
index 597cf49..32f6bd3 100644
--- a/VRANbs-API.md
+++ b/VRANbs-API.md
@@ -12,12 +12,14 @@ For the currently available public FarmMaps API you can take a look at swagger:
     * But API users can delete their own items through the farmmaps API.
 
 **Input preperation**
-* Users can upload their own soilmaps if needed. (in case of when FarmMaps has not processed the required data).
+* Users can upload their own data if needed. (in case of when FarmMaps has not processed the required data).
     * The farmmaps file API can be used for this.
 
 **Users can poll the task api to see if a task is completed**  
 **This can be achieved with the task execution id obtained from calling the 'ItemTask' API.**  
-**Users can query the API for child items of a cropfield to see what data it has.**
+[Poll task status](https://git.akkerweb.nl/FarmMaps/Documentatie/wiki/Polling-task-status)  
+
+**Users can query the API for child items of a cropfield to see what items it has.**
 
 ### API flow
 * Authenticate User
@@ -26,7 +28,7 @@ For the currently available public FarmMaps API you can take a look at swagger:
         * Item 'vnd.farmmaps.itemtype.cropfield' must be created with its data as specified in the api.
         * Task 'vnd.farmmaps.task.workflow' needs to be executed to aggregate all needed data.
             * This is an asynchronous process and can take a while before all data is collected in FarmMaps.
-    * *Upload own soil data*
+    * *Upload own data*
         * IF shape data, convert to geotiff.
     * *Create 'vnd.farmmaps.itemtype.user.input' item for targetn calculation.*
         * *Task 'vnd.farmmaps.task.vranbs' can be executed with the 'targetn' operation*
@@ -140,6 +142,7 @@ Response 404 Parent Item not found
 
 
 **Call the vranbs task**  
+Execute the VRANbsTask with the item code of the cropfield as parameter inside {code}. 
 Use the code obtained from creating the user.input item as a parameter in {itemCode}.  
 > Request
 ```javascript
@@ -149,6 +152,8 @@ POST /api/v1/items/{code}/tasks
   "attributes": {
       "operation": "targetn",
     "inputCode": "{itemCode}",
+    "plantingDate": "2020-02-01T00:00:00.000Z",
+    "measurementDate": "2020-06-01T00:00:00.000Z",
     "inputType": "irmi", // yara, ci, irmi or wdvi
     "purposeType": "consumption", // consumption, fries, potato, starch
     "targetYield": "60"
@@ -217,6 +222,8 @@ POST /api/v1/items/{code}/tasks
   "attributes": {
       "operation": "uptake",
       "inputCode": "{itemCode}",
+      "plantingDate": "2020-02-01T00:00:00.000Z",
+      "measurementDate": "2020-06-01T00:00:00.000Z",
       "inputType": "irmi", // yara, ci, irmi or wdvi
   }
 }
@@ -253,6 +260,8 @@ POST /api/v1/items/{code}/tasks
   "attributes": {
       "operation": "nitrogen",
       "inputCode": "{itemCode}",
+      "plantingDate": "2020-02-01T00:00:00.000Z",
+      "measurementDate": "2020-06-01T00:00:00.000Z",
       "inputType": "irmi", // yara, ci, irmi or wdvi
       "targetN": "249.22948"
   }
diff --git a/VRAPoten-API.md b/VRAPoten-API.md
index 7ddd063..aca10e5 100644
--- a/VRAPoten-API.md
+++ b/VRAPoten-API.md
@@ -12,8 +12,9 @@ For the currently available public FarmMaps API you can take a look at swagger:
 * Users can upload their own soilmaps if needed. (in case of when FarmMaps has not processed the required data).
     * The file API can be used for this.
 
-**Users can poll the task api to see if a task is completed**
+**Users can poll the task api to see if a task is completed**  
 **This can be achieved with the task execution id obtained from calling the 'ItemTask' API.**  
+[Poll task status](https://git.akkerweb.nl/FarmMaps/Documentatie/wiki/Polling-task-status)  
 
 ### API flow
 * Authenticate User