Characterizations of some classes of strong sign nonsingular digraphs. - Jia-Yu Shao; Zhi-Xiang Hu (Discret. Appl. Math., 2000)

Recursive Hilbert Transform Method: Algorithm and Convergence Analysis. - Zhi-Xiang Hu; Xiao Huang; Lunhai Zhi (Circuits Syst. Signal Process., 2024)