Piyada Chittanon. 1999. The effect of cryopreservation on structure and viability of spermatozoa of Rana tigerina. Faculty of Graduate Studies, Mahidol University;
Piyada Chittanon. (1999) The effect of cryopreservation on structure and viability of spermatozoa of Rana tigerina . Mahidol University/Bangkok.
Piyada Chittanon. The effect of cryopreservation on structure and viability of spermatozoa of Rana tigerina. . Bangkok:Mahidol University, 1999.
Piyada Chittanon. (1999) The effect of cryopreservation on structure and viability of spermatozoa of Rana tigerina . Mahidol University/Bangkok.