@book{7425,
	author = {International Astronomical Union colloqium and A'Hearn, M., ed. and International Astronomical Union},
	title = {The study of comets},
	publisher = {National Aeronautics and Space Administration},
	year = {1976},
	series = {NASA SP; 393},
	address = {Washington},
	note = {Donated by Mrs. Bappu}
}