1. Allen, C. W. 1973, Astrophysical Quantities (London: Athlone Press), chap. 9
2. Flux-Tube Model Atmospheres and Stokes [ITAL]V[/ITAL] Zero-crossing Wavelengths
3. Bevington, P. R. 1969, Data Reduction and Error Analysis for the Physical Sciences (New York: McGraw-Hill)
4. Bronshtein, I. N. & Semendyayev, K. A. 1985, Handbook of Mathematics (New York: Van Nostrand Reinhold Co.)