effect of different rates of ( 15-15.15) fertilizer on growth and yield of pok choy ( Brassica rapa var) ឥទិ្ធពលនៃកម្រិត​( ១៥.១៥.១៥) ផ្សេងៗគ្នានៅលើកាលូតលាស់ និងទិន្នផលដំណាំស្ពៃតឿ POU LADY ប៉ូ លេឌី ARG POU 2017 B630 Or.1 Phnom Penh RUA 2017 2017 Text viii;36p https://drive.google.com/file/d/1T1nLxnyH17uqfS6eRxZ3Nr6ImBA30yg0/view?usp=sharing