@article{GDZPPN002087510,
title = {Non-Orientable Surfaces in Orientable 3-Manifolds.},
journal = {Inventiones mathematicae},
volume = {9},
year = {1969},
pages = {83-110},
zbl = {0175.20504},
url = {http://dml.mathdoc.fr/item/GDZPPN002087510}
}
BREDON, G.E.; WOOD, J.W. Non-Orientable Surfaces in Orientable 3-Manifolds.. Inventiones mathematicae, Tome 9 (1969) pp. 83-110. http://gdmltest.u-ga.fr/item/GDZPPN002087510/