Wilkins, S., Stojic, N., Beale, T., Binggeli, N., Bencok, P., Stanescu, S., Mitchell, J., Abbamonte, P., Hatton, P., & Altarelli, M. (online). Evidence of Orbital Ordering in Jahn-Teller Undistorted LaSr$_{2}$Mn$_{2}$O$_{7}$