@book{16005,
	author = {Hopkins, Donald P.},
	title = {Chemicals, humus, and the soil : a simple presentation of contemporary knowledge and opinions about fertilizers, manures, and soil fertility},
	publisher = {Chemical publishing, },
	year = {1948.},
	address = {New York : },
	note = {Bibliogtaphy;: p.347-349}
}