otsego lake watershed, based on Jay A. Bloomfield (Hrsg.): Ecology of the Lakes of East-Central New York. Academic Press (Elsevier), 1980, <a href="//commons.wikimedia.org/wiki/Special:BookSources/9781483277349" title="Special:BookSources/9781483277349">ISBN 9781483277349</a>, p. 23
<a href="//commons.wikimedia.org/wiki/User:Kmhkmh" title="User:Kmhkmh">Kmhkmh</a>
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<span class="int-own-work" lang="en">Own work</span>