Asymmetric beams in cosmic microwave background anisotropy experiments - Wu, J; Balbi, A; Borrill, J; Ferreira, P; Hanany, S; Jaffe, A; Lee, A; Oh, S; Rabii, B; Richards, P; Smoot, G; Stompor, R; et al. (ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2001)