Bagtas, J. E., & Dyoco, R. N. (1999). The farmers of San Simon before and after the temporary closure of ugnayang magsasaka ng San Simon inc: A socio-economic analysis. University of the Philippines Diliman Extension Program in Pampanga.

Bagtas, Jonathan Esguerra, and Romeo N. Dyoco. The Farmers of San Simon Before and After the Temporary Closure of Ugnayang Magsasaka Ng San Simon Inc: A Socio-economic Analysis. Pampanga: University of the Philippines Diliman Extension Program in Pampanga, 1999.

Bagtas, Jonathan Esguerra, and Romeo N. Dyoco. The Farmers of San Simon Before and After the Temporary Closure of Ugnayang Magsasaka Ng San Simon Inc: A Socio-economic Analysis. University of the Philippines Diliman Extension Program in Pampanga, 1999.