"Tchad, Lac." . . "Ökologie." . . "Lake ecology." . . "Biological productivity Chad, Lake." . . . . "Naturhistorie" . . "Lake ecology Chad, Lake." . . "See Afrika." . . "Limnologie." . . "Africa" . . "Aufsatzsammlung." . . "Chad, Lake." . . "Tschadsee." . . "Biological productivity." . . "Écologie des lacs Tchad, Lac." . . "Productivité biologique Tchad, Lac." . . . . . . . . . . . . . "Lake Chad : ecology and productivity of a shallow trop. ecosystem" . . "Lake Chad : Ecology and productivity of a shallow tropical ecosystem" . . "Lake Chad Ecology and Productivity of a Shallow Tropical Ecosystem"@en . . . "Lake Chad Ecology and Productivity of a Shallow Tropical Ecosystem" . . . "Lake Chad : ecology and productivity of a shallow tropical ecosystem" . . "Electronic books"@en . . . . . "Aufsatzsammlung" . . . "Lake Chad ecology and productivity of a shallow tropical ecosystem"@en . . "Lake chad : ecology and productivity of a shallow tropical ecosystem" . "Lake Chad" . . . . . . . . . . . . . . . . . . . .