Ilcham, Adi, et al. “Bentonite-Based Drilling Boyolali Mud Fabrication With Additive Carboxymethyl Cellulose, Na2CO3 and KOH”. Journal of Earth Energy Engineering, vol. 12, no. 2, Oct. 2023, pp. 76-84, doi:10.25299/jeee.2023.13497.