Murty, MV. Ramana, P. Fini, GB. Stephenson, C. Thompson, JA. Eastman, A. Munkholm, O. Auciello, R. Jothilingam, SP. DenBaars, and JS. Speck,
"Step bunching on the vicinal GaN (0001) surface",
Physical Review B, vol. 62, no. 16: APS, pp. R10661, 2000.