APA (7th ed.) Citation

Horgan, J. (1994). Sex, death and sugar. Scientific American, 271(5), 20. https://doi.org/10.1038/scientificamerican1194-20

Chicago Style (17th ed.) Citation

Horgan, John. "Sex, Death and Sugar." Scientific American 271, no. 5 (1994): 20. https://doi.org/10.1038/scientificamerican1194-20.

MLA (9th ed.) Citation

Horgan, John. "Sex, Death and Sugar." Scientific American, vol. 271, no. 5, 1994, p. 20, https://doi.org/10.1038/scientificamerican1194-20.