GL Inquiry from subledger transactions (AP,AR,FA,CM)

Hi,

I would just like to know how will I be able to inquire on a transaction made from the subsidiary ledgers like AP,AR,FA and CM to General Ledger?

For example, I created an AP Invoice then posted invoice through Online Create Accounting or  I post in detail.Is there a reference number I can cross-check this invoice entries to GL?

As there will hundreds of journals posted, how will I know which journal is for a specific transaction? I there a reference number I can use?

Thank you very much,