@book { BiofuelEnergyspentcoffeegroundsbiodieselbioethanolandsolidfuel,
    title = "Biofuel Energy: spent coffee grounds biodiesel, bioethanol and solid fuel",
    author = "Mebrahtu {Haile}",
    year = "2014",
    publisher = "Anchor Academic Publishing",
    address = "Hamburg, Germany",
    url = "https://m.anchor-publishing.com/document/312762"
}