Now online, public Open Access back-issues of the CLIJ : Cuadernos de Literatura Infantil y Juvenil, 1988-2009. This is the venerable Spanish monthly on children’s literature and illustrators, and the online archive from #1 in 1988 runs to over 2,000 articles. The magazine’s focus is on young and middle-childhood, and as such the magazine is very well illustrated. It doesn’t appear to cover things for more mature teen readers, like the Toutain empire of the Heavy Metal-like comics magazines of the 1980s and 90s.
Search and viewing is per-page and as such rather clunky. One easier way to get full-issue PDFs is via Google Search…
site:www.cervantesvirtual.com/obra/ Lovecraft filetype:pdf
This also picks up post-2009 issues in .PDF format, and for instance I can get one from 2010 which would not be accessible via the site’s archive list. Some of the issue numbering seems to be astray, too. For instance, what downloads as clij-cuadernos-de-literatura-infantil-y-juvenil-137.pdf turns out to actually be #151.
Lead articles in CLIJ appear from random sampling to have a substantial focus on imported British and American culture in translation, and I see specials on R. L. Stevenson, J.M. Barrie, and American superhero comics as experienced in Spain (issue #151)…
#32 (1991) was a special on Gisbert, who was apparently strongly influenced by Lovecraft.
#80 (1996) had a survey of the stranger ends of fantasy literature, “From Zeus to Lovecraft”.
#236 (2010) had a long feature surveying horror literature in Spanish, for younger readers. Probably there are more specials to be found, if one wants to dig in.