Headache due to ERD.

I'm doing a simplified E. Relationship Diagram for our INTROSE project. And it made my head to hurt. I do not do this since last term and I need to refresh and reminisce on my notes just to remember ERDs. :D

Also, when I look back to my notes I remembered that last term, the only problem I had is the two MPs of INTRODB and INTROAI. *deleted some part here* =))

By the way, I would like to show the ERD that cause my headache. I think, maraming mali sa diagram namin. Ako may gawa eh. Hahaha!

View larger image here.

Saya! May note pa para kay Pau! Siya kasi mag computerized ng ERD namin. Di ko kasi kaya yun, pang papel lang ako eh. :D