Years based on the known dates of the Australian version of WAGS, which started before the British version and ended long after. It seems likely that other comic publications (possibly strips rather than books) were distributed earlier as the company may have started as early as 1933, but nothing has yet been confirmed.
Comics Detective blog entries:
http://thecomicsdetective.blogspot.com/2010/03/wonderful-wags-of-oz.html
http://thecomicsdetective.blogspot.com/2010/04/return-to-wonderful-wags-of-oz.html
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