UML 2 Certification Guide Fundamental and Intermediate Exams, Tim Weilkiens and Bernd Oestereich, Morgan Kaufman Publishers, ISBN-13: 918-0-12-373585-0, ISBN-10: 0-12-373585-8 Regards, Jan [ July 29, 2007: Message edited by: Jan Cumps ]
You may have to base your study on the UML Superstructure in conjunction with several other material sources to clarify the advanced concepts.
I'd recommend "The Unified Modeling Language Reference Manual, Second Edition" written by Rumbaugh, Jacobson and Booch. It's written in dictionary format, so not suitable for reading from cover to cover. However, it does explain the concepts really well and at times in depth (e.g. Association Class). Certainly better than just reading the Superstructure. It doesn't have very good coverage of OCL though.
Schaum's Outlines UML second edition by Simon Bennett, John Skelton & Ken Lunn has fairly good coverage of OCL. However, there are other areas of the OCUP Advanced syllabus that it doesn't cover.
I've come up with the conclusion that I'll need to study materials from several sources for the UML OCUP Advanced. However, in my case, I haven't decided whether I'll need to take the OCUP Advanced level because it's not really relevent to my business analysis work. Intermediate level is more than sufficient, especially when working in an agile environment. For example, why use OCL when plain English does the job ?
Anyway, that's my 2 cents. Good luck on your studies.