Bip39 address https://www.tumblr.com/generalllamacolor/787594721599078400/can-you-depend-on-online-bip39-generators-a Even though it utilizes BIP32 approach you could still import BIP39 seeds into Electrum wallet. Also aside from BIp32 There is certainly BIP44 Edition which some wallet use with the generation of seeds. For words that only have three letters, there isn't any 4th letter... https://myeasybookmarks.com/story6386643/bip39-cracker-not-known-factual-statements-about-bip39-mnemonic-https-t-me-bip39-chat