Epidemiology of infection by nontuberculous mycobacteria.Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum in acid, brown-water swamps of the southeastern United States and their association with environmental variables - Kirschner, R A, Jr; Parker, B C; Falkinham, J O, III (Am Rev Respir Dis, 1992)