General maxent
A. Berger, S. Della Pietra, and V. Della Pietra. A maximum entropy approach to natural language processing. Computational Linguistics, 22(1):39-71, 1996.
S. Della Pietra, V. Della Pietra, and J. Lafferty. Inducing features of random fields. Technical report, Carnegie Mellon University Computer Science Technical Report CMU-CS-95-144, 1995.
S. Guiasu and A. Shenitzer. The principle of maximum entropy. The Mathematical Intelligencer, 7(1), 1985.
E. Jaynes. Notes on present status and future prospects. In W.T. Grandy and L.H. Schick, editors, Maximum Entropy and Bayesian Methods, pages 1-13. Kluwer, 1990.
Scaling
D. Brown. A note on approximations to discrete probability distributions. Information and Control, 2:386-392, 1959.
I. Csiszár. I-divergence geometry of probability distributions and minimization problems. The Annals of Probability, 3(1):146-158, 1975.
I. Csiszár and G. Tusnády. Information geometry and alternating minimization procedures. Statistics & Decisions, Supplemental Issue:1, pages 205-237, 1984.
I. Csiszár. A geometric interpretation of Darroch and Ratcliff's generalized iterative scaling. The Annals of Statistics, 17(3):1409-1413, 1989.
J. Darroch and D. Ratcliff. Generalized iterative scaling for log-linear models. Ann. Math. Statistics, 43:1470-1480, 1972.
Of related interest
P. Brown, S. Della Pietra, V. Della Pietra, and R. Mercer. The mathematics of statistical machine translation: parameter estimation. Computational Linguistics, 19(2):263-311, 1991.
A. Dempster, N. Laird, and D. Rubin. Maximum likelihood from incomplete data via the em algorithm. Journal of the Royal Statistical Society, 39(B):1-38, 1977.
W. Feller. An introduction to probability theory and its applications, volume 1. John Wiley & Sons, 1957.
F. Jelinek and R. Mercer. Interpolated estimation of markov source parameters from sparse data. In Proceedings, Workshop on Pattern Recognition in Practice, 1980.
T. Cover and J. Thomas. Elements of Information Theory. John Wiley & Sons, 1991.