The Music and Musical Instruments of North Eastern India - Dilip Ranjan Barthakur - Google Books

http://books.google.de/books?id=oP4vH-4oSEcC&pg=PA129&dq=EKTARA&hl=de&ei=d6B5TLj8JZmX4gbW3-2BBg&sa=X&oi=book_result&ct=book-thum

A Comprehensive Study Dealing With Music Of North-Eastern India With Special Emphasis On Musical Instruments Of Assam. Has Over 75 Colour Illustrations Which Add To The Usefulness Of The Book.