Phimchanok Nakkharat; Arkom Tesnum; Arkira Maethawarakorn; Dietmar Haltrich; Chirakarn Muangnapoh. Characterization of a Crude Thermostable β-galactosidase by the Bacterium PD1 Isolated from the Pong Dueat Hot Spring. Agr. Nat. Resour. 2008, 42, 264-268.