TY - BOOK AU - Walford,A.J. TI - Walford's guide to reference material / PY - 1980///] CY - München : PB - G. K. Saur, KW - Obras de referencia- KW - Bibliografías N1 - Contiene: I: Science & technology. X, 697 p. -- II: Social & historical sciences, philosophy & religion ER -