1. Square multiples n give infinitely many cyclic n-roots. Reports;Backelin,1989
2. Representations of quantum permutation algebras;Banica;J. Funct. Anal.,2009
3. Teodor Banica, Ion Nechita, Jean-Marc Schlenker, Analytic aspects of the circulant hadamard conjecture, 2012. ArXiv Preprint arXiv:1212.3589.
4. Functions of modulus 1 on Zn whose Fourier transforms have constant modulus, and cyclic n-roots;Björck,1990
5. Generalized Hadamard matrices;Butson;Proc. Amer. Math. Soc.,1962