Query to display BOMs Header and Item

Hello SAP gurus

I am trying to create a query to display BOMs with header and item. For that I am using tables MAST, STKO and STPO.

The table join is:

MAST -> STKO -> STPO

MAST - WERKS, STLNR and STLAL

STKO - STLNR and STPOZ

The system dont show anything...

Can someone help me?

Thanks in advance.

Adelmo Silva