Ja-Ling Wu Yuh-Ming Huang J. Shiu Shyh-Huei Hsu Block Diagonal Structure in Discrete Transforms. 17-33 1989 5 J. Inf. Sci. Eng. 1 http://www.iis.sinica.edu.tw/page/jise/1989/198901_02.html db/journals/jise/jise5.html#WuHSH89