Kharel, Hari Lal, Ram Kumar Sharma, and Tanka Prasad Kandel. “Water Hardness Removal Using Wheat Straw and Rice Husk Ash Properties”. Nepal Journal of Science and Technology 17, no. 1 (August 5, 2016): 11–16. Accessed December 26, 2024. https://nepjol.info./index.php/NJST/article/view/25057.