Etihasik Bhashavigyan Aur Hindi Bhasha
By Gopal Kumar
This book is edited by Dr. Rajmal Bora. Actually, the material of this book is based on the four books of Ramvilas Sharma ('Bhasha Aur Samaj' & 'Bharat ke prachin bhasha Parivar Aur Hindi'- Part-1,2 and 3). The book is useful very much for the students of Linguistics.
I bought this book from 'infibeam' and fully satisfied. The book is available in Hardcover Edition (in very cheap rate). I don't know that there are available Paperback Edition of this book (or not) but this book is very useful.