@book{12217,
	author = {Seminar on Data Collection Techniques in the National Sample Survey, C. S. O. & I. S. I., Calcutta, June 1969 and Murthy, M. N. ; ed.},
	title = {Data collection techniques in the national sample survey; proceedings},
	publisher = {Department of Statistics},
	year = {1970},
	address = {New Delhi}
}