Storage of BW Master Data Documents

Hi,

What is the name of the database table where the BW Master Data Documents are stored? Furthermore, I need to be able to get the last changed date of the document in the database table.

I know that the Master Data Repository uses database table BWCONTMAST. But this table doesn't have a date.

I really need the date because I will be writing an ABAP program to delete old documents.

Thanks.