Bip39 library https://hubpages.com/@lefwenuuyr Though it uses BIP32 system it is possible to nonetheless import BIP39 seeds into Electrum wallet. Also aside from BIp32 There may be BIP44 version which some wallet use for the technology of seeds. For words that only have 3 letters, there isn't any 4th letter. By https://geniusbookmarks.com/story20596939/bip39-seed-phrases-not-known-details-about-bip39-word-list-txt-https-x-com-tundra838554