Portal:Reference works

General encyclopedias

 * The American Cyclopædia (1879)
 * The New International Encyclopædia (1905)
 * The Nuttall Encyclopædia (1907)
 * The Encyclopedia Americana (1906)
 * The Encyclopedia Americana (1920)
 * Collier's New Encyclopedia (1921)

Encyclopædia Britannica

 * Encyclopædia Britannica, Ninth Edition (1875–1889)


 * 1902 Encyclopædia Britannica (10th ed., supplement to the 9th)
 * 1911 Encyclopædia Britannica
 * 1922 Encyclopædia Britannica

Literature

 * Literary Research Guide (2017)

Places

 * Kansas: A Cyclopedia of State History

Biography

 * See Portal:Biography

Young people

 * The New Student's Reference Work

Religion

 * See a list of encyclopaedias on religion at Wikipedia.
 * Catholic Encyclopedia, 1913
 * Easton's Bible Dictionary
 * Jewish Encyclopedia

Music

 * A Dictionary of Music and Musicians
 * University Musical Encyclopedia

History

 * A Dictionary of Greek and Roman Antiquities

Botany

 * Twelve edible mushrooms of the United States

Classification

 * ICD-10-CM (2010)