We analyze superconductivity in (formula presented) observed below (formula presented) K resulting from electron-phonon coupling involving a mode at (formula presented) and, most importantly, the in-plane B-B (formula presented) vibration at (formula presented) The quasiparticles originating from (formula presented) states couple strongly to the low-frequency mode and the (formula presented) vibrations, respectively. Using two-band Eliashberg theory, (formula presented) and (formula presented) we calculate the gap functions (formula presented) (formula presented) (formula presented) Our results provide an explanation of recent tunneling experiments. We get (formula presented).