Gurewich, Nathan. Teach yourself visual 5 in 21days / Nathan Gurewich & Ori Gurewich - 4th ed. - Indianapolis : Sams, 1997 - xxvii, 907p. ; 23cm. ISBN: 0672309785 Subjects--Topical Terms: BASIC (Computer program language) Dewey Class. No.: 005.13 / GUR