Bip39 standalone http://www.mediafire.com/file/uilrjfajg2ami24/pdf-14673-57158.pdf The buy on the mnemonic phrase matters. If you mess up the buy then you cannot Get well your wallet. All your cash will likely be dropped forever. Ensure you have a correct backup. This functions simply because BIP39 is supported by a lot of wallet makers. https://travialist.com/story11008685/bip39-numbers-helping-the-others-realize-the-advantages-of-bip39-recovery-tool-https-cutt-ly-uryc5rw7