@book{20937,
	author = {Krithivasan, Kamala},
	title = {Discrete Mathematical Structures:},
	publisher = {Indian Insitiute of Technology},
	address = {Madras},
	url = {http://video.snu.edu.in/index.php?id=1436&cat=Computer Science and  Engineering&course=Discrete Mathematical Structures&url=Phase1_Video/106106094/lec30.mp4}
}