@book{94628,
	author = {Whittaker, E. T. and Robinson, George},
	title = {The calculus of observations},
	publisher = {Dover Publications},
	year = {[1967]},
	address = {New York},
	edition = {4th ed.},
	note = {"An unabridged and unaltered republication of the fourth edition (1944) of the work originally published ... in 1924."}
}