Comparative studies on the validity of the contract Comparative studies on the validity of the contract. Comparative studies on remedy for breach of the contract Comparative studies on remedy for breach of the contract. Comparative studies on tax regimes of BRICS countries Comparative study on standard building contract He tong xiao li bi jiao yan jiu/: Comparative studies on the validity of the contract, He tong xiao li bi jiao yan jiu =: Comparative studies on the validity of the contract/ He tong xiao li bi jiao yan jiu =: Comparative studies on the validity of the contract / Comparative study on the value theory of Marx and Adam Smith