51. X-Fighters: Usaf Experimental and Prototype Fighters, Xp-59 to Yf-23
by Pace, Steve 
Price: USD 4.87
Dealer: Alibris, ThriftBooks-Baltimore via Alibris
Description: Motorbooks International 1992 Softcover Good Pages can have notes/highlighting. Spine may show signs of wear. ~ ThriftBooks: Read More, Spend Less. 

52. X-Fighters
by Pace, Steve 
Price: USD 8.74
Dealer: Abebooks, Better World Books
Description: ISBN10: 0879385405, ISBN13: 9780879385408, [publisher: Motorbooks Intl] Softcover Former library book; may include library markings. Used book that is in excellent condition. May show signs of wear or have minor defects. [Mishawaka, IN, U.S.A.] [Publication Year: 1991]  

53. X-Fighters
by Pace, Steve 
Price: USD 8.41
Dealer: ZVAB, Better World Books
Description: ISBN10: 0879385405, ISBN13: 9780879385408, [publisher: Motorbooks Intl] Softcover Former library book; may include library markings. Used book that is in excellent condition. May show signs of wear or have minor defects. [Mishawaka, IN, U.S.A.] [Publication Year: 1991]