@book{31675,
	author = {M. Salman-ur-Rehman, Naila Masood & Muhammad Khan},
	title = {Billing Interface Through Web and Cellular Phone},
	publisher = {UITU,},
	year = {1999},
	address = {Karachi:},
	url = {https://drive.google.com/file/d/1LJw4dGlEDyOb0tCzC3MTrILnuERlKLup/view?usp=sharing}
}