Vintage: Celebrating the first Earth Day
Sale 1192 American Historical Ephemera & Photography by Hindman
Decades Ago at San Diego State, NewsCenter
The San Diego Union-Tribune: Feb. 6, 2022 Edition by
From the Archives: 1970: Balboa Park undergoes face-lift - The San
April 22, 1970: Earth Day · Exhibit · Give Earth a Chance
Decades Ago at San Diego State, NewsCenter
Earth Day - Wikipedia
Vintage: Celebrating the first Earth Day
This Day in History: The first Earth Day held in 1970
Earth Day PDFs combined - Celebrating earth day-Earth day