[3] A. Christ, A. Migdall, A. Fedrizzi, H. Hübel et al. Parametric down-conversion. Experimental Methods in the Physical Sciences, 351(2013).
[7] V. G. Dmitriev, G. G. Gurzadyan, D. N. Nikogosyan. Handbook of Nonlinear Optical Crystals, 64(2013).
[26] R. W. Boyd. Nonlinear Optics(2020).
[44] C. Lanczos, J. Boyd. Discourse on Fourier Series(2016).