Art. 57 CISG
(1) If the buyer is not bound to pay the price at any other particular place, he must pay it to the seller:
(a) at the seller's place of business; or
(b) if the payment is to be made against the handing over of the goods or of documents, at the place where the handing over takes place.
(2) The seller must bear any increases in the expenses incidental to payment which is caused by a change in his place of business subsequent to the conclusion of the contract.
The Secretariat Commentary on Art. 53 of the 1978 New York Draft, predecessor to Art. 57 CISG, gives insight into the drafters' unterstanding on the eve of the 1980 Vienna Diplomatic Conference.
Commentary on the Draft Convention on Contracts for the International Sale of Goods, prepared by the Secretariat (UN Doc. A/CONF.97/5), in: United Nations Conference on Contracts for the International Sale of Goods, Vienna, 10 March – 11 April 1980, Official Records: Documents of the Conference and Summary Records of the Plenary Meetings and of the Meetings of the Main Committees, New York: United Nations (1991), pp. 14 et seq., at pp. 45—46
Overview of case law on Art. 57 CISG: UNCITRAL Digest
The UNCITRAL Digest on the CISG can be used as a starting point to discover the relevant case law on this article.