@book{20162,
	author = {Ghosh, S.K.},
	title = {Modern Surveying Techniques:},
	publisher = {Indian Insitiute of Technology},
	address = {Delhi},
	url = {http://video.snu.edu.in/index.php?id=739&cat=Civil Engineering&course=Modern Surveying Techniques&url=Phase1_Video/105107121/lec06.mp4}
}