Radon-exposed underground miners and inverse dose-rate (protraction enhancement) effects - Lubin,J.H.; Boice Jr,J.D.; Edling,C.; Hornung,R.W.; Howe,G.; Kunz,E.; Kusiak,R.A.; Morrison,H.I.; Radford,E.P.; Samet,J.M. (Health Phys, 1995)