Not Always Buried Deep: A Second Course in Elementary Number Theory

How Numbers Work: Discover the strange and beautiful world of mathematics

An Introductory Course in Elementary Number Theory

Steps into Analytic Number Theory: A Problem-Based Introduction

A Beginner's Guide to Constructing the Universe: The Mathematical Archetypes of Nature, Art, and Science

Notebooks of Srinivasa Ramanujan: Volume II, Volume 2

Number Theory: Structures, Examples, and Problems

A History of Pi

Complex Numbers from A to ... Z: Edition 2

Ramanujan's Place in the World of Mathematics: Essays Providing a Comparative Study

Proof and the Art of Mathematics

God Created The Integers: The Mathematical Breakthroughs that Changed History

My Search for Ramanujan: How I Learned to Count

The Square Root of 2: A Dialogue Concerning a Number and a Sequence

Love and Math: The Heart of Hidden Reality