Parampalli Udaya M. U. Siddiqi Optimal and Suboptimal Quadriphase Sequences Derived from Maximal Length Sequences over Z<sub>4</sub>. 161-191 1998 9 Appl. Algebra Eng. Commun. Comput. 2 http://link.springer.de/link/service/journals/00200/bibs/8009002/80090161.htm db/journals/aaecc/aaecc9.html#UdayaS98