@article{701393,
     title = {A field equation defined by a Hurwitz pair},
     booktitle = {Proceedings of the Winter School "Geometry and Physics"},
     series = {GDML\_Books},
     publisher = {Circolo Matematico di Palermo},
     address = {Palermo},
     year = {1985},
     pages = {117-128},
     mrnumber = {MR0853134},
     zbl = {0613.35066},
     url = {http://dml.mathdoc.fr/item/701393}
}

Kalina, Jerzy; Lawrynowicz, Julian; Suzuki, Osamu. A field equation defined by a Hurwitz pair, dans Proceedings of the Winter School "Geometry and Physics", GDML_Books,  (1985), pp. 117-128. http://gdmltest.u-ga.fr/item/701393/