Yuwaree Punkla. 1991. Hyperrings and transformation semigroups admitting hyperring structure. Graduate School, Chulalongkorn University;
Yuwaree Punkla. (1991) Hyperrings and transformation semigroups admitting hyperring structure . Chulalongkorn University/Bangkok.
Yuwaree Punkla. Hyperrings and transformation semigroups admitting hyperring structure. . Bangkok:Chulalongkorn University, 1991.
Yuwaree Punkla. (1991) Hyperrings and transformation semigroups admitting hyperring structure . Chulalongkorn University/Bangkok.