9781444350890 | 4th edition (Blackwell Pub, May 8, 2012), cover price $47.95 | About this edition: This volume collects the most substantial correspondence and documents relating to Wittgenstein's long association with Cambridge between the years 1911 and his death in 1951, including the letters he exchanged with his most illustrious Cambridge contemporaries Russell, Keynes, Moore, and Ramsey (and previously published as Cambridge Letters).

9780205292707, titled "Educational Psychology: Theory and Practice" | 6th edition (Allyn & Bacon, August 1, 1999), cover price $72.00 | also contains Educational Psychology: Theory and Practice | About this edition: The Eighth Edition of this popular text from renowned educational psychologist Robert Slavin translates theory into practices that teachers can use in their classrooms with a further inquiry into the concept of intentionality and a thorough integration of standards.

9780415136679 | Routledge, June 12, 1997, cover price $610.00