6B [Choice of law of Contracting State];

8A; 8C3 [Interpretation of party's statements or other conduct: intent of party making statement or engaging in conduct; Interpretation in light of surrounding circumstances (usages)];

9B; 9D2 [Implied agreement on international usage; Usages implicitly made applicable to contract];

14A12 [Criteria for an offer (intention to be bound): determination of price];

55A3 [Open-price contracts: where parties intend to be bound, Article 55 upholds the agreement]