Bip39 test vectors https://www.giantbomb.com/profile/blathayqvn/ Regardless that it takes advantage of BIP32 process you can nevertheless import BIP39 seeds into Electrum wallet. Also apart from BIp32 There is certainly BIP44 Model which some wallet use for the era of seeds. For words that have only three letters, there's no 4th letter. https://bookmarkingdelta.com/story20397589/bip39-example-the-smart-trick-of-bip39-word-list-github-that-no-one-is-discussing-https-cutt-ly-uryc5rw7