Ungson, R. (1975). Abaca marketing, Part I: Bicol. Special Studies Division, Dept. of Agriculture.
Cita Chicago (17th ed.)Ungson, R.D. Abaca Marketing, Part I: Bicol. Quezon City: Special Studies Division, Dept. of Agriculture, 1975.
Cita MLA (9th ed.)Ungson, R.D. Abaca Marketing, Part I: Bicol. Special Studies Division, Dept. of Agriculture, 1975.
Atenció: Aquestes cites poden no estar 100% correctes.