"While these particular Tuttle textbooks are suitable for, and typically used in, classroom settings, including in some of the best universities in North America, they can also serve as an excellent out-of-class reference tool and can very well complement formal language classes or other study materials for the self-learner. From my experience, this series should appeal to a broad range of people, including individuals working on their own, professional people working with a tutor, or students in a classroom setting. I have personally used the Tuttle Elementary and Continuing textbooks both as part of university classes and on my own, and I have been very satisfied with them. --Lingholic blog"