Phase Portrait Generator (页面存档备份,存于互联网档案馆) a tool for sketching phase portraits of 2D systems. LinearPhase Portraits (页面存档备份,存于互联网档案馆), an MIT Mathlet.
McClellan, Chebyshev Approximation for Nonrecursive Digital Filters with LinearPhase, IEEE Trans. Circuit Theory, vol. CT-19, pp. 189-194, Mar. 1972. L.R
Bessieres, Manuel M. Piñeiro, Jean-Luc Daridon. Simultaneous estimation of phase behavior and second-derivative properties using the statistical associating