R, Z., J, D., & S, O. (1997). LASIK for myopia and astigmatism after penetrating keratoplasty. Journal of refractive surgery (Thorofare, N.J. : 1995), 13(6), 501. https://doi.org/10.3928/1081-597X-19970901-04
Chicago Style (17th ed.) CitationR, Zaldivar, Davidorf J, and Oscherow S. "LASIK for Myopia and Astigmatism After Penetrating Keratoplasty." Journal of Refractive Surgery (Thorofare, N.J. : 1995) 13, no. 6 (1997): 501. https://doi.org/10.3928/1081-597X-19970901-04.
MLA (9th ed.) CitationR, Zaldivar, et al. "LASIK for Myopia and Astigmatism After Penetrating Keratoplasty." Journal of Refractive Surgery (Thorofare, N.J. : 1995), vol. 13, no. 6, 1997, p. 501, https://doi.org/10.3928/1081-597X-19970901-04.
Warning: These citations may not always be 100% accurate.