Migrating from gnucash

Hi,
I started writing a script in PHP (don't know perl) to migrate from gnucash to SQL_Ledger, then I discovered ledgersmb and I'd prefer to use it over sql-ledger.
I managed to get all the data from gnucash, and now I need to write into the ledgersmb database.
I'll be offering the script to the community once I've finished it.
My question is:
Is there any documentation on which tables are written when adding:
A client/vendor
A transaction (sale/purchase)
An invoice (sale/purchase)

Thanks,
Federico