Welzer, H. (2013). Manfred Holtfrerich. artist : Kunstmagazin.
Lua i Stíl Chicago (17ú heag.)Welzer, Harald. "Manfred Holtfrerich." Artist : Kunstmagazin 2013.
Lua MLA (8ú heag.)Welzer, Harald. "Manfred Holtfrerich." Artist : Kunstmagazin, 2013.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.