Bip39 github http://www.mediafire.com/file/uilrjfajg2ami24/pdf-14673-57158.pdf Even though it uses BIP32 process you'll be able to even now import BIP39 seeds into Electrum wallet. Also apart from BIp32 There may be BIP44 version which some wallet use for your era of seeds. Want to examine which wallets assist the BIP39 mnemonic recovery seed https://friendlybookmark.com/story20347170/keystone-bip39-the-single-best-strategy-to-use-for-bip39-recovery-tool-https-x-com-tundra838554