Now some people on the team want to split this common table into several tables, and one for each type of item. To me that is absolutely unnecessary

...

I believe my design is correct in both cases, and I also believe those are common issues to lots of monks. But other than knowing what is right, I also need to show evidence that what I am doing is common practice and there are theoretical papers/books/TERMINOLOGIES/web sites behind, otherwise the discussion can go on for quite a while...

So um ... you've decided that your way is best, but you have absolutely no proof of it, so you want someone else to give you evidence of why your way is better?

I'm not sure if this is just complete trolling, or if you're serious. If you're serious, I suggest you give up, and listen to the others on the project. Your solution may functionally work, but it's not going to scale well. I suggest that you come up with the questions that you need to ask of the system, and then both you and the other person come up with solutions -- the other person's will likely be simpler, run faster, and can be more efficiently tuned (less overhead from useless indexing, more compact tables, etc.)

As for references, the best one I have is the Oracle Data Modeling guide, but I don't think it's available unless you take the class.