* Kak, Subhash (2014), "Number theoretic Hilbert transform", Circuits, Systems and Signal Processing, 33 (8): 2539–2548, arXiv:1308.1688, doi:10.1007/s00034-014-9759-8, S2CID 253639606 /wiki/Subhash_Kak
Kak, Subhash (2015), "Orthogonal residue sequences", Circuits, Systems and Signal Processing, 34 (3): 1017–1025, doi:10.1007/s00034-014-9879-1, S2CID 253636320 [1] /wiki/Subhash_Kak
Donelan, H. (1999). Method for generating sets of orthogonal sequences. Electronics Letters 35: 1537-1538.
Appuswamy, R., Chaturvedi, A.K. (2006). A new framework for constructing mutually orthogonal complementary sets and ZCZ sequences. IEEE Trans. Inf. Theory 52: 3817-3826.