@misc{misc86458908,
title   = {Some remarks on invariant surfaces and their extrinsic curvature},
author = {Mercuri, F and Montaldo, S and Onnis, Irene Ignazia},
year = {2011},
publisher = {AMS},
booktitle   = {Harmonic Maps and Differential Geometry : a Harmonic Map Fest in Honour of John C. Wood's 60th Birthday}
}