Comments on: The Effects of Density and Porosity on the Correlation Between Uniaxial Compressive Strength and P-wave Velocity by Amin Jamshidi, Hasan Zamanian, Reza Zarei Sahamieh, Rock Mechanics and Rock Engineering (2018) 51:1279–1286 - Saffet Yagiz (Rock Mechanics and Rock Engineering, 2019)