@book{847,
	author = {Hersh, Marion A. (Editors)},
	title = {Assistive Technology for Visually Impaired and Blind People },
	publisher = {Springer,},
	year = {2008.},
	address = {London :},
	url = {https://books.google.com.pk/books?id=HIBPnRAhh-gC&printsec=frontcover&dq=Assistive+Technology+for+Visually+Impaired+and+Blind+People&hl=en&sa=X&ved=0ahUKEwjUoojG7IXMAhVC1hoKHbawBH8Q6AEIGTAA#v=onepage&q=Assistive%20Technology%20for%20Visually%20Impaired%20and%20Blind%20People&f=false}
}