@book{90636,
	author = {Granville, William Anthony and Smith, Percey Franklin},
	title = {Trigonometría plana y esférica},
	publisher = {UTEHA},
	year = {1967.},
	series = {Mathematical texts, ed. by P.F. Smith},
	address = {México},
	edition = {3. ed. rev.}
}