1. The cost of soil erosion in Nicaragua;Alfsen;Ecological Economics,1996
2. Aruoba, Ç., 1997. Tarımsal Üretimde Doğal Kaynaklar. Türkiye’nin Tarım Politikası ve Çevre, TÇV Publication No. 122, pp. 89–91.
3. The costs of land degradation in Sub-Saharan Africa;Bojö;Ecological Economics,1996
4. Resource degradation, technical change, and the productivity of energy use in US Agriculture;Cleveland;Ecological Economics,1995
5. Ekbom, A., 2002. Optimal soil use. Göteborg University Environmental Economics Unit Seminars. Göteborg, Sweden (www.handels.gu.se/econ/EEU/Ekbom.Soiluse8.doc).