Once that is done, you can edit Wikipedia page Veni Creator Spiritus, replacing the newadvent link with {{wikisource-lang|la|Veni, Creator Spiritus}} and {{wikisource|Catholic Encyclopedia (1913)/Veni Creator Spiritus|"Veni Creator Spiritus"in Catholic Encyclopedia 1913}}.
 Notice that the local Wikipedia page has English lyrics, without attribution.  The Wikipedia talk page has a link, but those lyrics are slightly different.  A google search brings up one Wikipedia, so it is probable that it is based on the edition listed on the talk page, and adapted by Wikipedians.  i.e. it is OR.  Wikipedia is littered with these.  If I have time, I reconstruct the translation history from the Wikipedia edit history, in order to contact the contributors and try to establish that it is there own work or not, so that I can copy it over to Wikisource with only the appropriate attribution recorded for GFDL purposes, or ask those contributors to recreate the translation from a fresh slate on Wikisource.  As often as not, the contributors either cant be reached, or the contributors reply that they copied it from a modern work (i.e. illegal) - I can send you evidence of this if desired.  More thoughts on the yet to be written "Wikipedia is not Wikisource" essay here: Talk:Poetry_of_Catullus#Please stop tagging Catullus poems for (re)moval.  Only in the most obvious cases do I bother to remove the lyrics from the Wikipedia article, because usually I am reverted.