Reference
Sabine Kleinknecht, Hans G. Erkert, John E. Nelson (1984): Circadian and ultradian rhythms of activity and O2-consumption
in three nocturnal Marsupialian species: Petaurus breviceps,
Phalangeridae; Dasyuroides byrnei, Dasyuridae; Monodelphis
domestica, Didelphidae – Mammalian Biology (früher Zeitschrift für Säugetierkunde) – 50: 321 - 329.