• [Wiki] http://en.wikipedia.org/wiki/Tardigrada.
• [bumblebee] http://www.bumblebee.org/invertebrates/TARDIGRADA.htm.
• [Earth] http://www.eoearth.org/article/Tardigrada.
• [Baum1961] Baumann, H. (1961). Der Lebensablauf von Hypsibius (H.) convergens Urbanowicz (Tardigrada). Zoologischer Anzeiger, 167:363--381.
• [Grev1980] Greven, H. (1980). Die Baertierchen, volume 537 of Die Neue Brehm-Bucherei. A. Ziemsen Verlag, Wittenberg Lutherstadt.
• [Kooy2010] Kooijman, S. (2010). Dynamic Energy Budget theory for metabolic organisation. Cambridge Univ. Press, Cambridge.
• [MorgKing1976] Morgan, C. I. and King, P. E. (1976). British Tardigrades, volume 9 of Synopsis of the British Fauna. Academic Press, London.