Altınok, Selma; Bhupal, Mohan (2008), "Minimal page-genus of Milnor open books on links of rational surface singularities", Singularities II, Contemp. Math., vol. 475, Amer. Math. Soc., Providence, RI, pp. 1–10, doi:10.1090/conm/475/09272, ISBN978-0-8218-4717-6, MR2454357; see p.2: "Recall that the genus of a compact surface S with boundary is defined to be the genus of the associated closed surface obtained ... by sewing a disc onto each boundary circle"
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Altınok, Selma; Bhupal, Mohan (2008), "Minimal page-genus of Milnor open books on links of rational surface singularities", Singularities II, Contemp. Math., vol. 475, Amer. Math. Soc., Providence, RI, pp. 1–10, doi:10.1090/conm/475/09272, ISBN978-0-8218-4717-6, MR2454357; see p.2: "Recall that the genus of a compact surface S with boundary is defined to be the genus of the associated closed surface obtained ... by sewing a disc onto each boundary circle"
Altınok, Selma; Bhupal, Mohan (2008), "Minimal page-genus of Milnor open books on links of rational surface singularities", Singularities II, Contemp. Math., vol. 475, Amer. Math. Soc., Providence, RI, pp. 1–10, doi:10.1090/conm/475/09272, ISBN978-0-8218-4717-6, MR2454357; see p.2: "Recall that the genus of a compact surface S with boundary is defined to be the genus of the associated closed surface obtained ... by sewing a disc onto each boundary circle"