A conditional directional distance function approach for measuring regional environmental efficiency: Evidence from UK regions, European Journal of Operational Research, 227: 182-189

A conditional directional distance function approach for measuring regional environmental efficiency: Evidence from UK regions, European Journal of Operational Research, 227: 182-189 (SCOPUS, ISI Listed. Impact factor: 3.428 and 5-year 3.960). In common with N. Tzeremes (2013).