Tsyganenko, N. A., A magnetospheric magnetic field model with a warped tail current sheet
(Planet. Space Sci., v.37(1), pp.5-20, 1989) (PDF 1.0 MB)

Peredo, M., D. P. Stern, and N. A. Tsyganenko, Are existing magnetospheric models excessively stretched?
(JGR-A, v.98, 15343, 1993.) (PDF 1.2MB)