1. Ang M.H.: Group weighing matrices. Ph.D. Thesis, National University of Singapore, Singapore (2003).
2. Ang M.H., Ma S.L.: Symmetric weighing matrices constructed using group matrices. Des. Codes Cryptogr. 37, 195–210 (2005).
3. Ang M.H., Arasu K.T., Ma S.L., Strasslerd Y.: Study of proper circulant weighing matrices with weight 9. Discret. Math. 308, 2802–2809 (2008).
4. Arasu K.T., Dillon J.F.: Perfect ternary arrays: different sets, sequences and their correlation properties. NATO Advanced Science Institute Series C: Mathematical and Physical Sciences, vol. 542, pp. 1–15. Kluwer Academic Publishers, Dordrecht (1999).
5. Arasu K.T., Ma S.L.: Some new results on circulant weighing matrices. J. Algebraic Comb. 14, 91–101 (2001).