@article{article7511738c,
title   = {On the Maslov and the Morse index for constrained variational problems},
author = {Piccione, Paolo and Tausk, Daniel Victor},
year = {2002},
doi = {10.1016/s0021-7824(01)01225-9},
journal   = {Journal de Mathematiques Pures et Appliquees}
}