To cite a period found in PeriodO, you should cite the original source authority that defined the period:

Library of Congress Subject Headings, LC Linked Data Service, s.v. “China--History--Rebellion of the Three Feudatories, 1673-1681,” accessed July 20, 2020, http://id.loc.gov/authorities/subjects/sh95008524.html.

If you wish to credit PeriodO for helping you find the period's original source:

Library of Congress Subject Headings, LC Linked Data Service, s.v. “China--History--Rebellion of the Three Feudatories, 1673-1681,” http://id.loc.gov/authorities/subjects/sh95008524.html, found in PeriodO, s.v. “Rebellion of the Three Feudatories, 1673-1681,” accessed July 15, 2020, http://n2t.net/ark:/99152/p06c6g3hq7j.

To cite an editorial note added to an period by PeriodO curators, use the permalink for the period:

PeriodO, s.v. “Rebellion of the Three Feudatories, 1673-1681,” accessed July 15, 2020, http://n2t.net/ark:/99152/p06c6g3hq7j.

To cite an editorial note added to an authority by PeriodO curators, use the permalink for the authority:

PeriodO, s.v. “Library of Congress. Library of Congress Subject Headings. 2015.” accessed July 15, 2020, http://n2t.net/ark:/99152/p06c6g3.

To cite the PeriodO dataset as a whole, use the permalink for the dataset:

PeriodO: a gazetteer of periods for linking and visualizing data, accessed July 15, 2020, http://n2t.net/ark:/99152/p0.

Finally, if you wish to cite the PeriodO project please cite one of our publications, ideally one that is open access:

Rabinowitz, Adam, Ryan Shaw, Sarah Buchanan, Patrick Golden, and Eric Kansa. “Making Sense of the Ways We Make Sense of the Past: The Periodo Project.” Bulletin of the Institute of Classical Studies 59, no. 2 (2016). https://doi.org/10.1111/j.2041-5370.2016.12037.x.