@book{12062,
	author = {Hoel, Paul Gerhard, and Port, Sidney C.,},
	title = {Introduction to probability theory},
	publisher = {Houghton Mifflin},
	year = {[1971]},
	series = {The Houghton-Mifflin series in statistics},
	address = {Boston,},
	note = {Companion volume to the author's Introduction to statistical theory and Introduction to stochastic processes.}
}