Problem-Solving Strategies (Problem Books in Mathematics)

Problem-Solving Strategies by Arthur Engel: Used

Problem-Solving Through Problems (Problem Books in Mathematics) by Larson

Problem-Solving Strategies (Problem Books in Mathematics) by Engel, Arthur

Problem Books in Mathematics: Unsolved Problems in Number Theory by Richard...

Problem-Solving Strategies in Mathematics by Posamentier Alfred S: New

Problem-Solving Strategies by Arthur Engel: New Never Used 1998