Ruled surfaces with timelike rulings. - Nassar H. Abdel-All; Rashad A. Abdel-Baky; Fathi M. Hamdoon (Appl. Math. Comput., 2004)

A geometric characterisation of two-parameter spatial motions with many locally one-dimensional point paths. - Nassar H. Abdel-All; Fathi M. Hamdoon (Appl. Math. Comput., 2004)