https://ethereum.stackexchange.com/questions/38838/one-to-many-relationship-in-contract https://ethereum.stackexchange.com/questions/37988/mapping-1-to-many-ownership/37996#37996 https://bootvar.com/architecture-of-database-for-dapp/ https://ethereum.stackexchange.com/a/38582 https://docs.ipfs.tech/install/command-line/