S. Zak

Butorphanol: a double-blind evaluation in postoperative patients with moderate or severe pain

F. Caruso, F. Caruso, A. Dobkin, 1974, Canadian Anaesthetists' Society journal.

EEG and clinical changes in patients with chronic seizures associated with slowly growing brain tumors.

J. R. Hughes, S. Zak, 1987, Archives of neurology.