Use transaction SE11 to see whats in a table.
1. MSEG-MATNR, WERKS = MVER-Matnr, WERKS
2. MSEG with S031-Matnr, werks
3.
4.MSEG wtih S013-matnr, werks
5. Trying joining with MATNR, WERKS
After looking at a few of these, I believe you can join most of them through MATNR (material number) and WERKS (plant). Some may be connected with the purchasing document. However I think you are capable of accessing SE11 and searching the tables. Good Luck.
Regards,
C
