Bevitt, K. M. (11/3/2019). Ocean action newsletter (volume 9) March 2019. URL: https://sustainabledevelopment.un.org/content/documents/21681March_2019_Ocean_Action_Newsletter_final.pdf
The World Bank (WB); European Bank for Reconstruction and Development (EBRD); European Investment Bank (EIB), 'Enterprise Survey 2019 (North Macedonia)', 2020
Portugal Instituto Nacional de Estatística (INE); Minnesota Population Center (University of Minnesota), 'XII Recenseamento Geral da População e II Recenseamento Geral da Habitação 1981 - IPUMS Subset (Portugal)', 2016
Osafo, E.L.K. Evaluation of cereal crop residues: influence of species, variety and environment on nutritive value. Final Technical Report - Appendicies Part 1. October 1987-March 1991. AFRC Institute of Grassland and Environmental Research, UK. 191 pp. (1992)