I could only find this paper; see if it can help you:
K.V. Noren, A. Tarakji, "Macromodelling of positive IC voltage regulators". Int. J. Electronics, 1999, vol.86, no. 2, pag 153-172.
Abstract:
A macromodel for a fixed, positive, three-terminal, IC voltage regulator is presented. The macromodel models the important non-ideal effects of typical voltage regulators. The model can be used in both board-level design and as a block in a larger analogue VLSI design. Design formulas are provided so the model may be based on data sheet specifications or measured data. A design example is presented and compared to measured specifications.