@article{GDZPPN002066092,
title = {The fundamental group of compact manifolds without conjugate points.},
journal = {Commentarii mathematici Helvetici},
volume = {61},
year = {1986},
pages = {161-176},
zbl = {0608.53038},
url = {http://dml.mathdoc.fr/item/GDZPPN002066092}
}
Schroeder, Viktor; Croke, Ch.B. The fundamental group of compact manifolds without conjugate points.. Commentarii mathematici Helvetici, Tome 61 (1986) pp. 161-176. http://gdmltest.u-ga.fr/item/GDZPPN002066092/