Trials (Sub opportunities). Where to get details and history?.

CRM 7

I know that Trials are just sub opportunities. Within the Fact sheet there is already and opportunity assignment block showing certain information. I had a quick look at the code behind this with the aim of determining what method it used to extract the details, or maybe what tables are used.

Could I ask if anyone knows where these opportunity information is held (table-wise), how I can detect a sub-opportunity, and whether there are any FM's that might show these details for a particular account.

Jason