@book{12912,
	title = {Standard practice for description and identification of soils (visual-manual procedure) :},
	publisher = {ASTM International ,},
	year = {2006},
	address = {West Conshohocken, PA :},
	note = {This practice is under the jurusdiction  of ASTM Committee D18 on Soils and Rock and is the direct responsibility of Subcommittee D18.07 on Identification and Classification of Soils}
}