The book, SdKfz 251 In Action (# 21) covers the German Army's most widely produced half-track used during World War II.  The SdKfz 251 was produced in four models and twenty-three variants.  It served on all German combat fronts and contributed heavily to the early successes of the German panzer divisions.  This book includes the following: 1) More than 100 black and white photographs; 2) 10 color profiles; 3) 40 Black and white line drawings and 4) full color covers.  This book is 50 pages.  The author is Charles Kliment with Don Greer (illustrations).  Edition published in 1981.