Penny Nichols and the Mystery of the Lost Key

Appleton, Victor

Oppenheim, E. Phillips (Edward Phillips), 1866-1946

Freeman, R. Austin (Richard Austin), 1862-1943

Rees, Arthur J. (Arthur John), 1872-1942

Crane, Laura Dent

French, Joseph Lewis, 1858-1936 [Editor]

Alger, Horatio, Jr., 1832-1899

Carsey, Alice [Illustrator]; Sherwood, Elmer, 1884-

Finlay, Virgil, 1914-1971 [Illustrator]; Smith, George O. (George Oliver), 1911-1981

Hume, Fergus, 1859-1932

Wenzell, A. B. (Albert Beck), 1864-1917 [Illustrator]; Walk, Charles Edmonds, 1875-1943?