Gibbs RB, Nelson D, Anthony MS, Clarkson TB. Effects of long-term hormone replacement and of tibolone on choline acetyltransferase and acetylcholinesterase activities in the brains of ovariectomized, cynomologus monkeys. Neuroscience. 2002;113(4):907-14.
Poole WK, Pollack M, Rapoport I, Williams V, Koch MA, Rao AV, Bartel DA. Use of Multivariate Methods in Quantifying the Variability in the Perception of Neonatal Intensive Care Unit Characteristics in Nine Hospitals in the Washington, DC Area: the NIH-DC Initiative to Reduce Infant Mortality in Minority Populations in the District of Columbia. Interstat. 2002 Jan 1.