@article{700115,
     title = {Heteroclinic cycles in ecological differential equations},
     booktitle = {Equadiff 8},
     series = {GDML\_Books},
     publisher = {Mathematical Institute, Slovak Academy of Sciences},
     address = {Bratislava},
     year = {1994},
     pages = {105-116},
     mrnumber = {MR1298459},
     zbl = {0811.34035},
     url = {http://dml.mathdoc.fr/item/700115}
}

Hofbauer, Josef. Heteroclinic cycles in ecological differential equations, dans Equadiff 8, GDML_Books,  (1994), pp. 105-116. http://gdmltest.u-ga.fr/item/700115/