"These Happy Golden Years". Kirkus Reviews. October 1, 1939. Retrieved 2015-10-02. Online the review header shows a recent front cover, gives "volume 4" and "illustrated by Garth Williams".
loc.gov
lccn.loc.gov
"These happy golden years" (first edition). Library of Congress Online Catalog (catalog.loc.gov). Retrieved 2015-09-18.
Note [quoted]: "The end of the Little house books."–Page at end.