The assessment of narcotic analgesic drugs and of ligands with peptide structure by their actions on the morphine receptors in the guinea - pig ileum and mouse vas deferens Reprint not found: Hans W Kosterlitz, John Hughes,John A H Lord and Angela A Waterfield, 'The assessment of narcotic analgesic drugs and of ligands with peptide structure by their actions on the morphine receptors in the guinea - pig ileum and mouse vas deferens' reprinted from 'Representative 38th Meeting, Committee on Problems of Drug Dependence, NAS - NRC [The National Academy of Sciences - National Research Council]' (1976), 86 - 99. 1976