Stack, M M, E J Pentecost, and G Ravishankar. “Stochastic Frontier Analysis of Trade Efficiency for the New EU Member States: Implications of Brexit”. Economic Issues 23, no. 1 (March 1, 2018): 35–53. Accessed August 27, 2026. http://www.economicissues.org.uk/index.php/EI_OJS/article/view/292.