Berkeley Problems in Mathematics

Problem Books in Mathematics Ser.: Problem-Solving Through Problems

Challenging Problems in Algebra (Dover Books on Mathematics) - VERY GOOD

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

Challenging Problems in Geometry (Dover Books on Mathematics) - VERY GOOD

Problem Books in Mathematics Ser.: Berkeley Problems in Mathematics by ...

Practical Problems in Mathematics: For Welders (Applied Mathematics) - VERY GOOD

Polynomials (Problem Books in Mathematics) - E. J. Barbeau - Good - See cond...