^Preston KL, Bigelow GE, Liebson IA (March 1987). "Comparative evaluation of morphine, pentazocine and ciramadol in postaddicts". The Journal of Pharmacology and Experimental Therapeutics. 240 (3): 900–10. PMID3559982.
^Romagnoli A, Keats AS (1986). "Low ceiling respiratory depression by ciramadol". International Journal of Clinical Pharmacology Research. 6 (6): 451–5. PMID3100462.
^Downing JW, Brock-Utne JG, Holloway AM (December 1983). "Ciramadol--a new synthetic analgesic. A double-blind comparison with oral codeine for postoperative pain relief". South African Medical Journal = Suid-Afrikaanse Tydskrif vir Geneeskunde. 64 (25): 978–82. PMID6359486.
^Stambaugh JE, McAdams J (February 1987). "Comparison of the analgesic efficacy and safety oral ciramadol, codeine, and placebo in patients with chronic cancer pain". Journal of Clinical Pharmacology. 27 (2): 162–6. doi:10.1002/j.1552-4604.1987.tb02178.x. PMID3680568. S2CID21229861.