Gonzalez, J. (2014). SNSequate: Standard and Nonstandard Statistical Models and Methods for Test
Equating. Journal of Statistical Software, 59(7), 1-30.
Kolen, M., and Brennan, R. (2004). Test Equating, Scaling and Linking.
New York, NY: Springer-Verlag.
Johnson, D. H., and Sinanovic, S. (2000). Symmetrizing the Kullback-Leibler distance (Technical
report). IEEE Transactions on Information Theory.