"An Introduction to Number Theory" by Harold Stark is a textbook published in 1971 as part of the Markham Mathematics Series. It covers the subject area of mathematics with a focus on number theory. The book is written in English and is a hardcover edition with 347 pages. The author, Harold M. Stark, provides a comprehensive introduction to the fundamentals of number theory, making it a valuable resource for students and educators in the field of mathematics.