The first two items are the primary references for this program.
Eppler, Richard; and Somers, Dan M.:
A Computer Program for the Design and Analysis of Low-Speed Airfoils.
NASA Technical Memorandum 80210, August 1980.
Eppler, Richard; and Somers, Dan M.:
Supplement to: A Computer Program for the Design and Analysis of Low-Speed Airfoils.
NASA Technical Memorandum 81862, December 1980.
Eppler, Richard: Airfoil Design and Data. Springer-Verlag Berlin, 1990.
ISBN 3-540-52505-X.
Eppler, Richard: Airfoil Program System, User's Guide; Institut A fuer
Mechanik, Universitaet Stuttgart (1988).
Abbott, Ira H.; Von Doenhoff, Albert E.; and Stivers, Louis S., Jr.:
Summary of Airfoil Data.
NACA Report 824, March 1945.
Abbott, Ira H.; and Von Doenhoff, Albert E.: Theory of Wing Sections.
Dover Publications, Inc., c.1959.
Schlichting, Hermann (J. Kestin, transl.): Boundary Layer Theory.
McGraw-Hill Book Co., Inc., 1955.
Smetana, Frederick O.; Summey, Delbert C.; Smith, Neill S.; and Carden, Ronald K.:
Light Aircraft Lift, Drag, and Moment Prediction - A Review and Analysis.
NASA Contractor Report 2523, 1975.
Eppler, R.: Direct Calculation of Airfoils From Pressure Distribution.
NASA TT F-15,417, 1974. (Translated from Ingenieur-Archiv, vol. 25,
no. i, 1957, pp- 32-57.)
Lighthill, M. J.: A New Method of Two-Dimensional Aerodynamic Design.
R. & M. No. 2112, British A.R.C., 1945.
Hess, John L.: The Use of Higher-Order Surface Singularity Distributions
To Obtain Improved Potential Flow Solutions for Two-Dimensional Lifting
Airfoils. Computer Methods Applied Mechanics and Engineering, vol. 5, no. 1, Jan. 1975,
pp. 11-35.
Eppler, R.: Practical Calculation of Laminar and Turbulent Bled-Off
Boundary Layers. NASA Technical Memorandum 75328, 1978. (Translated from Ingenieur-
Archiv, vol. 32, 1963, pp. 221-245.)
Eppler, Richard; and Somers, Dan M.: Low Speed Airfoil Design and Analysis.
Advanced Technology Airfoil Research - Volume I, NASA CP-2045, Part l,
1979, pp. 73-99.
Kowalik, J.; and Osborne, M. R.: Methods for Unconstrained Optimization
Problems. American Elsevier Pub. Co., Inc., 1968.
Eppler, R. (Francesca Neffgen, transl.): Laminar Airfoils for Reynolds
Numbers Greater Than 4 x l06. B-819-35, Apr. 1969. (Available from
NTIS as N69-28178.) (Translated from Ingenieur-Archiv, vol. 38, 1969,
pp. 232-240.)
Eppler, Richard: Turbulent Airfoils for General Aviation. Journal of Aircraft,
vol. 15, no. 2, Feb. 1978, pp. 93-99.
Squire, H. B.; and Young, A. D.: The Calculation of the Profile Drag of
Aerofoils. R. & M. NO. 1838, British A.R.C., 1938.
Woods, L. C.: The Theory of Subsonic Plane Flow. Cambridge Univ. Press,
c.1961.
Drela, M.: XFOIL: An Analysis and Design System for Low Reynolds Number Airfoils.
In Lecture Notes in Engineering: Low Reynolds Number Aerodynamics.
T.J. Mueller (ed.) vol 54, Springer-Verlag, New York, June 1989.