Egger, Peter H ; Larch, Mario ; Yotov, Yoto V https://epub.uni-bayreuth.de/id/eprint/6135/1/Economica%20-%202021%20-%20Egger%20-%20Gravity%20Estimations%20with%20Interval%20Data%20Revisiting%20the%20Impact%20of%20Free%20Trade%20Agreements.pdf.
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2022