Nguyen T.B. et al. Syntheses of carbon-¹¹ labeled piperidine esters as potential in vivo substrates for acetylcholinesterase. Nucl. Med. Biol.1998, 25, 761–768.
Iyo M. et al. Measurement of acetylcholinesterase by positron emission tomography in the brains of healthy controls and patients with Alzheimer's disease. Lancet 1997, 349, 1805–1809.
Kikuchi T. et al. Piperidinyl and pyrrolidinyl butyrates as radiotracers for measuring cerebral butyrylcholinesterase activity evaluation in rats. J. Labelled Compd. Radiopharm.2001, 44, Suppl. 1, 322.