@book{7973,
	author = {Joint ILO/WHO Committee on Occupational Health (1968 : Geneva). and World Health Organization},
	title = {Permissible levels of occupational exposure to airborne toxic substances : sixth report of the Joint ILO/WHO Committee on Occupational Health [meeting held in Geneva from 4 to 10 June 1968].},
	publisher = {World Health Organization,},
	year = {1969.},
	series = {(WHO technical report series ; 415)},
	address = {Geneva : }
}