Sweet, H. Practical study of languages: A guide for teachers and learners.
Chicago-стиль цитированияSweet, Henry. Practical Study of Languages: A Guide for Teachers and Learners.
MLA-цитированиеSweet, Henry. Practical Study of Languages: A Guide for Teachers and Learners.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.