Bip39 html https://hubpages.com/@lefwenuuyr While it makes use of BIP32 approach you can still import BIP39 seeds into Electrum wallet. Also aside from BIp32 There may be BIP44 Edition which some wallet use for that generation of seeds. For words that have only 3 letters, there is absolutely no 4th letter. https://bookmarksurl.com/story5786311/bip39-to-binary-bip39-compatible-wallet-can-be-fun-for-anyone-https-cutt-ly-uryc5rw7