@book{38534,
	author = {Williamson, Benjamin,},
	title = {An elementary treatise on the integral calculus containing applications to plane curves and surfaces, and also a chapter on the calculus of variations, with numerous examples.},
	publisher = {Longmans, Green, and co.,},
	year = {1891.},
	address = {London:},
	edition = {6th ed., rev. & enl.}
}