@book { ShadermitGLSL,
    title = "Shader mit GLSL",
    subtitle = "Eine Einführung in die OpenGL Shading Language",
    author = "Heiko {Ihde}",
    year = "2009",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836628716",
    url = "https://m.diplom.de/document/226735"
}