I have just discovered a new google feature that maybe most of you already know about, but I need to share anyway.
I needed detailed information on significance of WISC-IV test-retest differences, and there is not that much available on that topic. So I looked through a few books, a few google searches, and finally found a treasure trove.
Google books lets you look up a few pages of a book that deals with a topic that you are searching on. So I finally found the tables giving me information on significant differences between two assessment scores in Pediatric Forensic Neuropsychology by Sherman and Irooks. The book was published in 2012, and is not available electronically. Well, apart from these precious few pages that answered my question. Brilliant.
Be careful using this resource, though. Google Books need to abide by copyright laws, and there are viewing limits for books. Once you exceed them, you cannot look up things in that book any more.
Still, it is worth it for these tricky questions.