Works by Dirichlet and Voronoi have been translated from German and French into English by Tiyapan. Also the latter have given a brief introduction to the study of Voronoi tessellation.Tiyapan graduated B.Sc. from Ramkhamhaeng University and B.Eng. from Chulalongkorn University, both in Thailand. He finished an M.Sc. at UMIST, England, began his Ph.D. study at Tokyo Institute of Technology and completed it at University of Manchester, England. His doctoral thesis (2004) was on Percolation and Voronoi Tessellation, namely percolation within percolation within Voronoi structures.These translations have been done during the beginning of his Ph.D. project in Manchester.