Single Variable Calculus: An Introduction to Integration is a free and open textbook and is a great introduction to integration for students who have already taken courses in differential calculus. The book explains Calculus II concepts adequately, comprehensively, and concisely, and its topics are reflective of the content areas in other published Calculus textbooks. Problems in the textbook do not only test computational skills, but are also applicable and related to real-life problems and areas that students are interested in. The text gives an adequate picture of Calculus II – Integral Calculus and prepares students for other disciplines like Engineering and Physics, as well as higher-level Mathematics courses.