How to relate BSIK and J_1BNFLIN?

Hi,

I need to create a new report that merges FBL1N data with J_1BNFLIN data. So, As FBL1N brings BSIK data, I need to find a way to relate this table to J_1BNFLIN table. I've tried to get AWKEY from BKPF with BSIK-BELNR, then I fetched J_1BNFLIN comparing REFKEY to BKPF-AWKEY. But in this last point, it doesn't work. Which is table I should fetch with BKPF-AWKEY in order to find J_1BNFLIN related data?