ماخذ: Guide to the Practical Study of Harmony. Translated by Emil Krall and James Liebling from the German version by P. Juon. Book.
ترجمه: راهنمای مطالعه عملی هماهنگی. پیتر ایلیچ چایکوفسکی. Guide to the Practical Study of Harmony composed by Peter Ilyich Tchaikovsky. 1840-1893.