Bip39. Entropy values has to be sourced from a solid supply of randomness. This implies flipping a good coin, rolling a good dice, sounds measurements etc. Will not use phrases from books, lyrics from songs, your birthday or steet address, keyboard mashing, or anything at all you believe is random, https://mynichedirectory.com/listings13104363/bip39-github-https-linktr-ee-bip39-details-fiction-and-bip39-word-list-pdf