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Thomas JM, Misiewicz JJ, Cook AR, Hill MJ, Smith PL, Walters CL, Forster JK, Martin LE, Woodings DF.Thomas JM, et al. Among authors: walters cl.Gut. 1987 Jun;28(6):726-38. doi: 10.1136/gut.28.6.726.Gut. 1987.PMID: 3623220Free PMC article.
Ruddell WS, Bone ES, Hill MJ, Walters CL.Ruddell WS, et al. Among authors: walters cl.Lancet. 1978 Mar 11;1(8063):521-3. doi: 10.1016/s0140-6736(78)90550-0.Lancet. 1978.PMID: 76069