Bramich, N J; Brock, J A; Edwards, F R; Hirst, G D . (1994). Ionophoretically applied acetylcholine and vagal stimulation in the arrested sinus venosus of the toad, Bufo marinus.. The Journal of Physiology, 478(2), 289–300.
doi:10.1113/jphysiol.1994.sp020250