Videos to FL and FP: John Backus: Function Level Programming and the FL Language 1987 (https://www.youtube.com/watch?v=FxcT4vK01-w&t=15s), John Backus Group Meeting - IBM Research - 5 July 1989 (https://www.youtube.com/watch?v=KzBkb-bvNK4), Backus on functional programming (https://www.youtube.com/watch?v=OxuPZXXiwKk) from Original: Oral History of John Backus (https://www.youtube.com/watch?v=dDsWTyLEgbk)