I. Sabry, “?CAFFEINE INJECTION IN THE DARK PHASE PROLONGS THE NOCTURNAL RISE IN SEROTONIN N-ACETYLTRANSFERASEACTIVITY AND MELATONIN CONTENT IN THE PINEAL GLAND OF MALE RATS”, Pakistan Journal of Scientific & Industrial Research, vol. 42, no. 1, pp. 27–29, Feb. 1999.