http://general-terms.thesaurus.ekt.gr/vocabhttp://general-terms.thesaurus.ekt.gr/vocab?tema=8417limnology http://general-terms.thesaurus.ekt.gr/vocab?tema=8417 aquatic ecology RT http://general-terms.thesaurus.ekt.gr/vocab?tema=8417 aquatic plants RT http://general-terms.thesaurus.ekt.gr/vocab?tema=8417 aquatic biology RT http://general-terms.thesaurus.ekt.gr/vocab?tema=8417 freshwater ecology RT http://general-terms.thesaurus.ekt.gr/vocab?tema=8417 hydrology BT