Aanen, P., Knottnerus, H.W., Bohemen, H.D. van, Centrum voor Landbouwpublikaties en Landbouwdocumentatie, Wageningen, Dienst Weg- en Waterbouwkunde, Delft€ 14,00
Jeffrey A McNeely, International Union for Conservation of Nature and Natural Resources., Workshop on the Economics of Protected Areas (1992 : Caracas, Venezuela)€ 20,00
Jeffrey A McNeely, International Union for Conservation of Nature and Natural Resources., Workshop on the Economics of Protected Areas (1992 : Caracas, Venezuela)€ 20,00