An Empirical Study of Visual Labs. - Marian G. Williams; William A. Ledder; J. Nicholas Buehler; James T. Canning (VL, 1993)

Appropriateness of Graphical Program Representations for Training Applications. - Marian G. Williams; Hyxia Villegas; J. Nicholas Buehler (CHI Conference Companion, 1996)

A study of program entry time predictions for application-specific visual and textual languages. - Marian G. Williams; J. Nicholas Buehler (ESP, 1997)

Comparison of visual and textual languages via task modeling. - Marian G. Williams; J. Nicholas Buehler (Int. J. Hum. Comput. Stud., 1999)