Sound On Sound, a UK magazine focusing on music recording technology, has a 6-page article about the recording of “Take On Me” in its latest issue, March 2011.
Describing the studio work on the different versions of the song in great detail, the article features contributions from producer Alan Tarney and engineers Neill King and Gerry Kitchingham.
The March issue of the magazine can be ordered from soundonsound.com. The a-ha article is also available as a PDF file here (includes a preview of the article).
(Thanks to Oliver and Matthew for the tip)