- https://books.google.com/books?id=aMRqDwAAQBAJ&pg=PA262&dq=georg+biedenkapp&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwjCve3r4O6EAxVYkYkEHQTSA9kQ6AF6BAgKEAI#v=onepage&q=georg%20biedenkapp&f=false
- https://archive.org/details/beer-and-revolution/page/172/mode/1up?q=biedenkapp
- https://books.google.com/books?id=Qw9uN50BI98C&pg=PA69&dq=georg+biedenkapp&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwjCve3r4O6EAxVYkYkEHQTSA9kQ6AF6BAgGEAI#v=onepage&q=georg%20biedenkapp&f=false
- https://books.google.com/books?id=-kTPEAAAQBAJ&pg=PA678&dq=georg+biedenkapp&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwihrqW74u6EAxXUlYkEHU_nB7U4FBDoAXoECA0QAg#v=onepage&q=georg%20biedenkapp&f=false
- 1843–1924 is different from 1868–1924[1]? Died in the same year?