The distance to SN 1999em from the expanding photosphere method - Hamuy, Mario; Pinto, Philip A; Maza, José; Suntzeff, Nicholas B; Philips, M M; Eastman, Ronald G; Smith, R C; Corbally, C J; Burstein, D; Li, Yong; Ivanov, Valentin; Moro-Martin, Amaya; et al. (The Astrophysical Journal, 2001)