@article{701458,
     title = {Graded Riemann surfaces and Krichever-Novikov algebras},
     booktitle = {Proceedings of the Winter School "Geometry and Physics"},
     series = {GDML\_Books},
     publisher = {Circolo Matematico di Palermo},
     address = {Palermo},
     year = {1990},
     pages = {15-24},
     mrnumber = {MR1061785},
     zbl = {0717.17001},
     url = {http://dml.mathdoc.fr/item/701458}
}

Bryant, Peter. Graded Riemann surfaces and Krichever-Novikov algebras, dans Proceedings of the Winter School "Geometry and Physics", GDML_Books,  (1990), pp. 15-24. http://gdmltest.u-ga.fr/item/701458/