Não informado. (1976). Illinois Natural History Survey Special Publications. Department of Energy and Natural Resources, Natural History Division.
Chicago-viite (17. p.)Não informado. Illinois Natural History Survey Special Publications. Champaign, Ill: Department of Energy and Natural Resources, Natural History Division, 1976.
MLA-viite (8. p.)Não informado. Illinois Natural History Survey Special Publications. Department of Energy and Natural Resources, Natural History Division, 1976.
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