Nugroho, Maris Setyo, et al. “The Effect of Mortar Mixture Variations on the Compressive Strength and Ultrasonic Pulse Velocity”. Inersia : Jurnal Teknik Sipil Dan Arsitektur, vol. 18, no. 2, Dec. 2022, pp. 225-34, doi:10.21831/inersia.v18i2.55256.