The Estavelle and the Inversac are two celebrated springs in the Mediterranean Languedoc (South of France). Unfortunately, the first one has been chosen as a type for the karstic cavities alternatively absorbing or discharging the waters, according to the season, which has never been the case. On the opposite, the second one can be taken as model for this alternation as swallow hole or emergence.
Les mésaventures des sources de L'Estavelle et de L'Inversac en Languedoc Méditerranéen.
International Journal of Speleology,
Available at: http://scholarcommons.usf.edu/ijs/vol16/iss3/4