APA (7th ed.) Citation

Krebs, T., & Johansen, P. (2013). Over 30 million psychedelic users in the United States. F1000Research, 2(98), . doi:10.12688/f1000research.2-98.v1

Chicago Style (17th ed.) Citation

Krebs, T.S, and P.O Johansen. "Over 30 Million Psychedelic Users in the United States." F1000Research 2, no. 98 (2013). https://doi.org/10.12688/f1000research.2-98.v1.

MLA (9th ed.) Citation

Krebs, T.S, and P.O Johansen. "Over 30 Million Psychedelic Users in the United States." F1000Research, vol. 2, no. 98, 2013, https://doi.org/10.12688/f1000research.2-98.v1.