I have it as 1938, but as you say some references are for 1937.
The dates are given in square brackets  and  and this date does not relate to the specific date of judgement, but to the edition of the law journal in which they were published.
Wilsons & Clyde Coal Co. Ltd v English  3 All ER 628 is the report in the All England Law Report from 1937
Wilson and Clyde Coal Co Ltd v English [ 1938 ] AC 57 (HL) 141 is the report in the Appeals Cases House of Lords reports from 1938
If you want a more complete explanation of the citation systems used in UK law publications you should have a look at the Oxford Standard for Citation of Legal Authorities... available from Oxford Univerity's websitehttp://www.law.ox.ac.uk/publications/oscola.php
If it isn't broken, that doesn't mean you can't improve it. (Do three negatives make a positive ?)