We showed this letter to Dr. Norman who replied as follows

Eitemau Tebyg

• We showed the letter from Dr. D'Souza to Dr. Davies and Dr. Hambleton, who replied as follows
  gan: Hambleton, Garry, et al.
  Cyhoeddwyd: (1976)
• We showed the letter by Dr. Rolles and his colleagues to Dr. Lamabadusuriya and his colleagues, who replied as follows
  gan: Lamabadusuriya, S. P., et al.
  Cyhoeddwyd: (1975)
• Dr. Erhardt's letter was referred to Harold A. Harper, Phd, who replies as follows
  gan: Harper, Harold A.
  Cyhoeddwyd: (1978)
• This letter was shown to Dr Joosten and colleagues who reply as follows
  gan: Joosten, E.
  Cyhoeddwyd: (1993)
• We showed Dr. Bose's letter to the CMA's director of educational services, who made the following comments
  gan: Harrison, Alexandra
  Cyhoeddwyd: (1988)