Zukauskas, Albertas; Matulaitiene, Ieva; Paipulas, Domas; Niaura, Gedinimas; Malinauskas, Mangirdas; Gadonas, Roaldas (2015). "Tuning the refractive index in 3D direct laser writing lithography: towards GRIN microoptics". Laser & Photonics Reviews. 9 (6): 706–712. Bibcode:2015LPRv....9..706Z. doi:10.1002/lpor.201500170.
Marchand, E.W. (1976). "Third-order aberrations of the photographic Wood". Journal of the Optical Society of America. 66 (12): 1326–1330. doi:10.1364/JOSA.66.001326.
Hecht, Eugene; Zając, Alfred (1987). Optics (2nd ed.). Reading, Mass.: Addison-Wesley. p. 178. ISBN978-0201116090. OCLC13761389.
Mohr, R K; Wilder, J A; Macedo, P B; Gupta, P K (1979). "Graded index lenses by the molecular stuffing process". A digest of technical papers presented at the Topical Meeting on Gradient Index Optical Imaging Systems, May 15-16, 1979, Rochester, New York. paper WA1. Washington, D C: Optical Society of America. OCLC489755284.
Luneburg, Rudolf Karl (1964). Mathematical Theory of Optics. Berkeley: University of California Press. ISBN978-0-5203-2826-6. OCLC1149437946.