1913 Great Meteor ProcessionW
1913 Great Meteor Procession
Bergius processW
Bergius process
Bohr modelW
Bohr model
ParsecW
Parsec
Principia MathematicaW
Principia Mathematica
Ringelmann effectW
Ringelmann effect
Roosevelt–Rondon Scientific ExpeditionW
Roosevelt–Rondon Scientific Expedition
Solar eclipse of April 6, 1913W
Solar eclipse of April 6, 1913
Solar eclipse of August 31, 1913W
Solar eclipse of August 31, 1913
Solar eclipse of September 30, 1913W
Solar eclipse of September 30, 1913