@book { Howcollagesrevealyourdeepestthoughts,
    title = "How collages reveal your deepest thoughts",
    author = "Philipp {Pachler}",
    year = "2012",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783656196976",
    url = "https://www.hausarbeiten.de/document/194454"
}