@article{articlea5ba6795,
title   = {The Maslov index and a generalized Morse index theorem for non-positive definite metrics},
author = {Piccione, Paolo and Tausk, Daniel Victor},
year = {2000},
doi = {10.1016/s0764-4442(00)01630-x},
journal   = {Comptes Rendus de l'Académie des Sciences - Series I - Mathematics}
}