1. C.J.R. Sheppard, A. Choudhury, Image formation in the scanning microscope. Optica Acta 24, 1051–1073 (1977)
2. C.J.R. Sheppard, The generalized microscope, in Confocal and Two-Photon Microscopy: Foundations, Applications and Advances, ed. by A. Diaspro (Wiley-Liss, 2002), pp. 1–18
3. S. Mehta, C.J.R. Sheppard, Quantitative phase-gradient imaging at high resolution with asymmetric illumination-based differential phase contrast. Opt. Lett. 34, 1924–1926 (2009)
4. M. Bertero, E.R. Pike, Resolution in diffraction-limited imaging, a singular value analysis I. The case of coherent illumination. Optica Acta 29, 727–746 (1982)
5. C. de Mol, Resolution enhancement by data inversion techniques, in Trends in Optics: Research, Developments and Applications, ed. by A. Consortini (Academic Press, 1996), pp. 281–297