Hartono, P., Pratikto, P., Suprapto, A. and Irawan, Y.S. 2018. Aloe vera as cutting fluid optimization using response surface method. Eastern-European Journal of Enterprise Technologies. 1, 1 (91) (Feb. 2018), 55–63. DOI:https://doi.org/10.15587/1729-4061.2018.123223.