New designs of low/high‐pass and mid‐pass/stop FIR digital filters. - Ishtiaq Rasool Khan; Ryoji Ohba (Int. J. Circuit Theory Appl., 2001)

New designs of frequency selective FIR digital filters. - Ishtiaq Rasool Khan; Masahiro Okuda; Ryoji Ohba (ISCAS (4), 2003)

Chebyshev Functions-Based New Designs of Halfband Low/Highpass Quasi-Equiripple FIR Digital Filters. - Ishtiaq Rasool Khan; Ryoji Ohba (EURASIP J. Adv. Signal Process., 2003)

Digital differentiators for narrow band applications in the lower to midband range. - Ishtiaq Rasool Khan; Masahiro Okuda; Ryoji Ohba (ISCAS (4), 2005)