Stiefel-Whitney surfaces and the tri-genus of non-orientable 3-manifolds.

W. Heil, V. Nunez, J. C. Gomez-Larranaga

Manuscripta Math. 100 (1999), no. 4, 405--422

BibTeX entry:

@article {MR2001a:57026,
    AUTHOR = {Heil, Wolfgang and N{\'u}\~{n}ez, V{\'\i}ctor and
              G{\'o}mez-Larra\~{n}aga, J. C.},
     TITLE = {Stiefel-{W}hitney surfaces and the tri-genus of non-orientable
              $3$-manifolds},
   JOURNAL = {Manuscripta Math.},
  FJOURNAL = {Manuscripta Mathematica},
    VOLUME = {100},
      YEAR = {1999},
    NUMBER = {4},
     PAGES = {405--422},
      ISSN = {0025-2611},
     CODEN = {MSMHB2},
   MRCLASS = {57M50 (57N10)},
  MRNUMBER = {2001a:57026},
MRREVIEWER = {Joan Porti},
}