Articles in Popular Science Monthly edit
Articles in The New International Encyclopædia edit
Works about Clark edit
Some or all works by this author are in the public domain in the United States because they were published before January 1, 1929.
This author died in 1947, so works by this author are in the public domain in countries and areas where the copyright term is the author's life plus 76 years or less. These works may be in the public domain in countries and areas with longer native copyright terms that apply the rule of the shorter term to foreign works.
Public domainPublic domainfalse