Measuring sustainable tourism UNWTO Committee of Statistics (2021), Measuring the Sustainability of Tourism (MST): progress and way forward, p.12 UNWTO, 2018, Linking the TSA and The SEEA: A technical note Spilanis I., 2017, Proposal for an evaluating framework of the sustainability of tourism activity, UNWTO, Committee on Statistics and TSA, Madrid 24-25/1/17