They appeared in ‘Dublin: A Portrait’ by V. S. Pritchett, a renowned travel writer and short story writer who visited Ireland in the 1960's and met with Sean O'Casey and WB Yeats during which Yeats brandished a tea pot in a rage about Shaw.
For more info on Evelyn Hofer see here:
https://en.wikipedia.org/wiki/Evelyn_Hofer
For more info on VS Pritchett:
https://en.wikipedia.org/wiki/V._S._Pritchett