1. Determinants, efficiency and potential of agri-food exports from Nigeria to the EU: Evidence from the stochastic frontier gravity model;N M Abdullahi;Agriculture Economics,2021
2. Examining the determinants and efficiency of China's agricultural exports using a stochastic frontier gravity model;N M Abdullahi;PlosOne,2022
3. Formulation and estimation of stochastic frontier production function models;D Aigner;Journal of Econometrics,1977
4. A theoretical foundation for the gravity equation;J E Anderson;The American Economic Review,1979
5. Examination of forest products trade between Turkey and the European Union countries with gravity model approach;K C Aky�z;African Journal of Biotechnology,2010