vol.1 was called "Hello! Project Complete Single Book", a guide book for Hello! Project's CD singles.
Vol.2 is a "Hello! Project Complete Album Book" (CDjournal), release is 3/18
http://tower.jp/item/3819171/HELLO!-PRO ... ALBUM-BOOK
detailed information of the albums and mini albums from Morning Musume, Berryz, C-ute, Angerme (Smileage), Melon Kinenbi, Matsuura Aya, Mano Erina, and other H!P album releases.