APA
Ma Y., National Bureau of Economic Research, Zhang M. & Zimmermann K. (2026). Business concentration around the world. Cambridge: NBER.
Chicago
Ma Yueran, National Bureau of Economic Research, Zhang Mengdi and Zimmermann Kaspar. 2026. Business concentration around the world. Cambridge: NBER.
Harvard
Ma Y., National Bureau of Economic Research, Zhang M. and Zimmermann K. (2026). Business concentration around the world. Cambridge: NBER.
MLA
Ma Yueran, National Bureau of Economic Research, Zhang Mengdi and Zimmermann Kaspar. Business concentration around the world. Cambridge: NBER. 2026.