Manobo Dictionary of Manobo as Spoken in the Agusan River Valley and the Diwata Mountain RangeGelacio T.E., Lee J.K., Schumacher R.L.PDF
Caraga Antigua 1521-1910: The Hispanization and Christianization of Agusan Surgao and East Davao (San Carlos Humanities Series, No 18)Melchizedek. Maquiso1989PDF