Provan, G; Cowley, SWH; Sandhu, J; Andrews, DJ; Dougherty, MK; (2013) Planetary period magnetic field oscillations in Saturn's magnetosphere: Postequinox abrupt nonmonotonic transitions to northern system dominance. Journal of Geophysical Research: Space Physics , 118 (6) pp. 3243-3264. 10.1002/jgra.50186. Green open access