@article{1104202033,
author = {Vaysburd, I. and Radul, A.},
title = {Nonorientable strings},
journal = {Comm. Math. Phys.},
volume = {135},
number = {2},
year = {1991},
pages = { 413-420},
language = {en},
url = {http://dml.mathdoc.fr/item/1104202033}
}
Vaysburd, I.; Radul, A. Nonorientable strings. Comm. Math. Phys., Tome 135 (1991) no. 2, pp. 413-420. http://gdmltest.u-ga.fr/item/1104202033/