Não informado. (2019). Newsletter. Pennsylvania State University, Environmental Resources Research Institute.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Newsletter. University Park, Pa: Pennsylvania State University, Environmental Resources Research Institute, 2019.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Newsletter. Pennsylvania State University, Environmental Resources Research Institute, 2019.
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