Using self join on a table to compare two fields based on a linked field in the same table : I have the following:

    TableA
    
    ID|DocumentType|DocumentCode|DocumentDate|Warehouse|RefecenceCode|
      
    1 |DeliveryNote|  DOC-001   | 2017-04-21 |    1    |     NULL    |
    2 |Invoice     |  DOC-002   | 2017-04-21 |    2    |    DOC-001  |


As you can see, the warehouse is different on each document and DOC-002 is related to DOC-001 through the information in `ReferenceCode` column (which means that was created starting from DOC-001 as a source document). It is supposed for the DOC-002 to have the same information but sometimes might be different and in this case, I was tried to create a query (I thing `self join` applies here) in order to check what information is different in the DOC-002 in this case compared to DOC-001, based on the reference code, but I couldn't managed to do it. If someone could give me a hand, I'll be very grateful. Thanks!