I think it's mostly a copy/paste from the specification.
Specification documents are Persistence(256 pages) + core(562 pages) but Mikalai Zaikin's guide is only 334 pages including Appendix.Are there topics that are not required for the exam but given in the specifications.
I read Bill Burke's book on Enterprise JavaBeans 3.0 (skipped the WebServices and JBoss chapters) and then I took the standard practise exams with the EJB+ Enthuware Software. When finding a weak spot presented in the evaluation of one exam, I studied that objective in MZ's study guide, then I took the next exam and repeated the procedure. I'd say you can easily pass the exam without reading the specs, if you want to.
MZ's chapter on Persistence Contexts and Persistence Units are very well written in my opinion.