Historical handbook series.
APA Citation
United States. National Park Service. Historical handbook series. Washington D.C.: U.S. Govt. Print. Off., Supt. of Docs.
MLA Citation
United States. National Park Service. Historical Handbook Series. Washington D.C.: U.S. Govt. Print. Off., Supt. of Docs,
Warning: These citations may not always be complete (especially for serials).