4B [Scope of Convention (issues excluded): burden of proof];
6B [Selection of law of a Contracting State = agreement to apply Convention];35D [Conformity of goods to contract (burden of proof): determined by domestic law];
78A ; 78B [Interest on delay in receiving price or any other sum arrears; Rate of interest];
84A [Seller bound to refund price must pay interest: formal request for payment of interest not required]