Citation: Mf. Cheng et Mx. Zuo, PROPOSED PATHWAYS FOR VOCAL SELF-STIMULATION - MET-ENKEPHALINERGIC PROJECTIONS LINKING THE MIDBRAIN VOCAL NUCLEUS, AUDITORY-RESPONSIVE THALAMIC REGIONS AND NEUROSECRETORY HYPOTHALAMUS, Journal of neurobiology, 25(4), 1994, pp. 361-379