1. Communications patterns in innovation development, Extension and client systems;Ambastha,1986
2. Heterogeneity, omitted variable bias, and duration dependence;Chamberlain,1985
3. Contact farmer selection and extension visits: The training and visit extension system in Haryana India;Feder;Quarterly Journal of International Agriculture,1984
4. Adoption of agricultural innovations in developing countries: A survey;Feder;Economic Development and Cultural Change,1985
5. Early adoption of improved vertisol technology options and double cropping in Begumgunj, Madhya Predesh;Foster,1987