New distribution records of amphibians in Vu Quang National Park, Ha Tinh Province, Vietnam: 1 = Leptobrachium masatakasatoi; 2 = Xenophrys cf. parva; 3 = Xenophrys lancangica; 4 = Quasipaa cf. verrucospinosa; 5, 6 = Amolops compotrix; 7, 8 = Kurixalus odontotarsus.