Oskar Bätschmann, born 1943, has been a professor for art history at University of Bern, Switzerland, 1991 2009. He has been a Professorial Fellow at Swiss Institute for Art Research SIK-ISEA in Zürich and is, together with Paul Müller, chief editor of the catalogue raisonné of Ferdinand Hodler's paintings. Monika Brunner read art history and ethnology and has been a research assistant for the catalogue raisonné of Ferdinand Hodler's paintings at Swiss Institute for Art Research SIK-ISEA in Zürich since 2009. Paul Müller, born 1951, is art historian and has been, together with Oskar Bätschmann, chief editor of the catalogue raisonné of Ferdinand Hodler's paintings at Swiss Institute for Art Research SIK-ISEA in Zürich since 2000. Bernadette Walter, born 1968, is art historian and curator at Neues Museum Biel NMB (New Museum Biel). She has been a research assistant for the catalogue raisonné of Ferdinand Hodler's paintings at Swiss Institute for Art Research SIK-ISEA in Zürich 2008-12.