Inquiry-Based Enumerative Combinatorics : One, Two, Skip a Few... Ninety-Nine...

Undergraduate Texts in Mathematics Ser.: Methods of Mathematical Economics :...

Undergraduate Texts in Mathematics Ser.: Undergraduate Algebra by Serge A. Lang

Constructive Combinatorics (Undergraduate Texts in Mathematics) by

Undergraduate Texts in Mathematics Ser.: Explorations in Monte Carlo Methods

Undergraduate Texts in Mathematics Ser.: First Course in Real Analysis by Murray

Undergraduate Texts in Mathematics Ser.: Calculus II by Alan Weinstein and ...

Undergraduate Texts in Mathematics Ser.: The Real Numbers : An Introduction...