A counterexample is given to a result of Perez which makes a statement about the convergence of a sequence of logarithms of Radon-Nikodym derivatives. The result, if true, would have been a generalization of the Shannon-McMillan theorem of information theory.
"A Counterexample to Perez's Generalization of the Shannon-McMillan Theorem." Ann. Probab. 1 (2) 362 - 364, April, 1973. https://doi.org/10.1214/aop/1176996994