1. Alcácer J, Delgado M (2013) Spatial organization of firms and location choices through the value chain. Harvard Business School Working Paper 13–025
2. ArcGIS Pro (2017) Retrieved Aug 25, 2017 from http://pro.arcgis.com/en/pro-app/tool-reference/spatial-statistics/multi-distance-spatial-cluster-analysis.htm
3. Angel SS, Blei A (2015) Commuting and the Productivity of American Cities. New York University, Marron Institute of Urban Management
4. Bessen J (2015) Learning by doing. Yale University Press, New Haven
5. Boulding KE (1966) The economics of knowldge and the knowledge of economics. Am Econ Rev 56(1/2):1–13