Carrie S Cutler
The problems in this book come from several editions of the text for our University of Houston Teaching Problem Solving class, Crossing the River with Dogs: Problem Solving for College Students. We highly recommend this resource for locating rigorous problems.
Johnson, K., & Herr, T. (2001). Crossing the river with dogs: Problem solving for college students. Wiley.

Johnson, K., Herr, T., and Kysh, J. (2003). Crossing the river with dogs: Problem solving for college students. Wiley.

Johnson, K., Herr, T., and Kysh, J. (2018). Crossing the river with dogs: Problem solving for college students. Wiley.
