An Extension of Eklundh's Matrix Transposition Algorithm and Its Application in Digital Image Processing. - Richard E. Twogood; Michael P. Ekstrom (IEEE Trans. Computers, 1976)

Design of stable 2-D half-plane recursive filters using spectral factorization. - Michael P. Ekstrom; Richard E. Twogood; John W. Woods (ICASSP, 1978)

Why filter recursively in two dimensions? - Richard E. Twogood; Michael P. Ekstrom (ICASSP, 1979)

2-D Digital signal processing with an array processor. - Richard E. Twogood (ICASSP, 1980)