T. W. Knight, “Designing with Grammars,” in G. N. Schmitt, ed., Computer-Aided Architectural Design (Verlag Viewag, Weisbaden, 1992), pp.33-48; T. W. Knight, “Color Grammars: the Representation of Form and Color in Design,” Leonardo 26 (1993): 117-124; T. W. Knight, “Shape grammars and color grammars in design,” Environment and Planning B: Planning and Design 21 (1994): 705-735.