Beyer, H. O. 1. (1961). Philippine tektites: A contribution to the study of the tektite problem in general, in the light of both past and recent discoveries. [Office of Research Coordination, University of the Philippines].

Beyer, Henry Otley 1883. Philippine Tektites: A Contribution to the Study of the Tektite Problem in General, in the Light of Both Past and Recent Discoveries. Quezon City: [Office of Research Coordination, University of the Philippines], 1961.

Beyer, Henry Otley 1883. Philippine Tektites: A Contribution to the Study of the Tektite Problem in General, in the Light of Both Past and Recent Discoveries. [Office of Research Coordination, University of the Philippines], 1961.