Παραπομπή σε μορφή APA (7η εκδ.)

Williams, R. C. (2000). Environmental tax interactions when pollution affects health or productivity. National Bureau of Economic Research.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Williams, Roberton C. Environmental Tax Interactions When Pollution Affects Health or Productivity. Cambridge: National Bureau of Economic Research, 2000.

Παραπομπή σε μορφή MLA (9th εκδ.)

Williams, Roberton C. Environmental Tax Interactions When Pollution Affects Health or Productivity. National Bureau of Economic Research, 2000.