Quelques remarques sur les diagrammes de Heegard
Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 3, Tome 24 (1970) no. 1, p. 37-52 
@article{ASNSP_1970_3_24_1_37_0,
     author = {Po\'enaru, Valentin},
     title = {Quelques remarques sur les diagrammes de Heegard},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     publisher = {Scuola normale superiore},
     volume = {3e s{\'e}rie, 24},
     number = {1},
     year = {1970},
     pages = {37-52},
     zbl = {0218.55004},
     mrnumber = {270376},
     language = {fr},
     url = {http://www.numdam.org/item/ASNSP_1970_3_24_1_37_0}
}

Poénaru, Valentin. Quelques remarques sur les diagrammes de Heegard. Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 3, Tome 24 (1970) no. 1, pp. 37-52. http://www.numdam.org/item/ASNSP_1970_3_24_1_37_0/

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