Rock drills used in South African mines: a comparative study of noise and vibration levels Authors: Phillips J, Heyns S, Nelson G. Source: Annals of Occupational Hygiene. 2007;51:305-310. Babalwa Jekwa2019-03-25T11:41:42+02:00May 24th, 2007| Share This Page, Choose Your Platform! FacebookTwitterLinkedInWhatsappEmail