@book{54223,
	author = {Mukhopadhayay, Parimal},
	title = {Theory and Methods of Survey Sampling},
	publisher = {PHI Learning,},
	year = {2012.},
	address = {New Delhi:},
	url = {https://books.google.com.pk/books?id=Et5aizm6KYoC&pg=PA462&lpg=PA462&dq=theory+and+methods+of+survey+sampling+by+mukhopadhyay+pdf&source=bl&ots=yoVOLovTLn&sig=Ui37m9C0o3JLaQu1-F3wef6wutA&hl=en&sa=X&ved=0ahUKEwiuhJn_kr7PAhUCOBQKHa2NBQgQ6AEIPDAF#v=onepage&q=theory%20and%20methods%20of%20survey%20sampling%20by%20mukhopadhyay%20pdf&f=false}
}