Fatkhan, F., Nugraha, A.D. and Syahputra, A. 2013. Determining Velocity and Q-factor Structure using Crosshole Tomography. Journal of Mathematical and Fundamental Sciences. 45, 1 (Mar. 2013), 29-38. DOI:https://doi.org/10.5614/j.math.fund.sci.2013.45.1.3.