1. J.F. Hoelscher, IEEE PVSC, 1981, p. 745.
2. PV industry information service Report PC-11, July 2000, Strategies Unlimited and Private communications, Bob Johnson Strategies Unlimited.
3. M.I. Smokler, IEEE PVSC, 1985, p. 1150 (and commercial data sheets).
4. A. Goetzberger, A. Ruber, 4-PVSEC., Sydney, 1999, p. 135.
5. H. Watanabe, 4-PVSEC., Sydney, 1999, p. 103.