https://librivox.org/all-about-coffee-by-william-ukers/https://www.gutenberg.org/files/28500/28500-h/28500-h.htmhttps://archive.org/details/allaboutcoffee0000unsehttps://archive.org/details/earlyhistoryofco00robi/page/n7/mode/2uphttps://www.google.com/books/edition/Le_caf%C3%A9ier_et_le_caf%C3%A9/lfcaAAAAYAAJ?hl=en&gbpv=1https://books.google.com/books?id=NstBAAAAIAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=falsehttps://archive.org/details/cu31924000870968https://archive.org/details/coffeeitshistory00wals/page/n7/mode/2uphttps://archive.org/details/sim_editor-publisher_1954-01-23_87_4/page/58/mode/2up?q=ukershttps://www.covoyacoffee.com/