Richards, Georgia C and Aronson, Jeffrey K and Heneghan, Carl and Mahtani, Kamal R and Koshiaris, Constantinos and Persaud, Nav (2020) Relation between opioid consumption and inclusion of opioids in 137 national essential medicines lists. BMJ Global Health, 5, (11), e003563. doi: 10.1136/bmjgh-2020-003563.