I recently started reading the public domain Barsoom novels (I'm on Thuvia, Maid of Mars at the moment) and I'm planning on reading the rest of the novels by Edgar Rice Burroughs, but some are in the public domain and some are not. As such, if anyone has any clue as to when each of his books will enter the public domain that would be rather useful information for me (assuming that public domain laws do not change between now and then).
In the US
According to this source, for works published between 1923 and 1963 where the copyright has been renewed, copyright expires 95 years after the publication date. From Wikipedia, "Chessmen of Mars" (1922) should be the last in public domain; the Barsoom books published between 1928 and 1963 will enter public domain between 2023 (Master Mind of Mars, 1928) and 2043 (!!: Llana of Gathol, 1948).
I'm not 100% sure the copyrights have been renewed but I strongly suspect they have because ERB established Edgar Rice Burroughs Inc. to control his intellectual property. (ERB Inc has also been fighting to prevent adaptations and other use of ERB characters and settings that are already in public domain (under trademark law), but that presumably won't affect the ability to reprint/publish the works as is.)
In the UK (?)
(according to this site) copyright is life+70 years = 2020.
I notice there are some Barsoom books on Gutenberg in Australia if you are still interested: http://gutenberg.net.au/searchresults.html