Word + Bib. Even though it employs BIP32 approach it is possible to even now import BIP39 seeds into Electrum wallet. Also besides BIp32 there is BIP44 version which some wallet use for the technology of seeds. The tool will advise various choices for the missing word plus the suitable https://angelojvepz.oneworldwiki.com/6389889/the_anatomy_of_the_bip39_phrase_entropy_phrases_and_protection