Merkel, K. (2000). Trilogy of stone and time: Klaus Merkel (Limited edition, numbered and signed by the artist.). Lars Müller Publishers.
Chicago-referens (17:e uppl.)Merkel, Klaus. Trilogy of Stone and Time: Klaus Merkel. Limited edition, numbered and signed by the artist. Zürich, Switzerland: Lars Müller Publishers, 2000.
MLA-referens (8:e uppl.)Merkel, Klaus. Trilogy of Stone and Time: Klaus Merkel. Limited edition, numbered and signed by the artist. Lars Müller Publishers, 2000.
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