Diaz, V. L. C., Salinas, J. T. I., & Colongon, A. A. J. (1989). Assessment of secondary materials on the provinces of Ifugao, Mountain Province and Nueva Vizcaya, 1978-1989. Cordillera Studies Center, University of the Philippines Baguio.
Chicago-referens (17:e uppl.)Diaz, Victoria Lourdes C., Jorge T. II Salinas, och Arellano A. Jr Colongon. Assessment of Secondary Materials on the Provinces of Ifugao, Mountain Province and Nueva Vizcaya, 1978-1989. Baguio City: Cordillera Studies Center, University of the Philippines Baguio, 1989.
MLA-referens (9:e uppl.)Diaz, Victoria Lourdes C., et al. Assessment of Secondary Materials on the Provinces of Ifugao, Mountain Province and Nueva Vizcaya, 1978-1989. Cordillera Studies Center, University of the Philippines Baguio, 1989.