Note: The work was originally published in two volumes, 1906 and 1907, and the same true of the first English-language translation, by Velma Swanston Howard 1907 and 1911. English Wikipedia (above) covers both titles, and thus the series, in a single article. The entire work has been published sometimes in one volume under the original title--at least in Swedish, and in the Howard translation as The Wonderful Adventures of Nils. Other translations should be examined on this point.