Burton, C.K., 1972. Outline of the geological evolution of Malaya. Journal of Geology, 80, 293 – 309.
Hamada, T., 1969. Late Palaeozoic brachiopods from red beds in the Malayan Peninsula. Geology and Palaeontology of Southeast Asia, 6, 251 – 267, Tokyo University Press.
Hamada, T., 1970. Devonian brachiopods from Kroh, Upper Perak in Malaysia. Geology and Palaeontology of Southeast Asia, 7, 1 – 13, Tokyo University Press.
Hamada, T., Igo, H., Kobayashi, T. and Koike, T., 1975. Older and Middle Palaezoic formations and fossils of Thailand and Malaysia. Geology and Palaeontology of Southeast Asia, 15, 1 – 38, Tokyo University Press.
Jones, C.R., 1968b. Malayan Early to Mid-Palaeozoic Stratigraphy and the Siluro-Devonian Graptolite Faunas of the Malay Peninsula. University of Birmingham PhD. thesis, (unpublished).
Jones, C.R., 1973. The Siluro-Devonian graptolite faunas of the Malay Peninsula. Overseas Geology and Mineral Resources, 44, Institute of Geological Sciences, London.
The Malaysia-Thailand Border Joint Geological Survey Committee (MT-JGSC), 2009. Geology of the Pengkalan Hulu - Betong transect area along the Malaysia - Thailand border. Minerals and Geoscience Department Malaysia.
