If there is a DOI:
Author last name, author first initial. (Year). Article title. Journal title, volume(issue, if available), pages. DOI
If there is no DOI, then end the citation with the page numbers:
Author last name, author first initial. (Year). Article title. Journal title, volume(issue), pages.
Author last name, author first initial. (Year). Book title. Publication city: Publisher name.
Brown, L. R. (2011). World on the edge: How to prevent environmental and economic collapse. New York: W. W. Norton.
If there is no DOI, then cite the ebook as if it were print book:
Author last name, author first initial. (Year). Ebook title.Publication city: Publisher name.
Cohen, S., Wannemacher, J., & Weisbecker, P. (2014). Understanding environmental policy (2nd ed.). New York: Columbia University Press.
Author last name, author first initial. (Date). Article title. Retrieved from website address.
Note: for a website, the author frequently will be the name of an organization.
World Agroforestry Centre. (2019). What is agroforestry? Retrieved from http://www.worldagroforestry.org/about/agroforestry