Bureau des Longitudes (1933). „Mesures employées sur les cartes marines”. Annuaire Pour l'An 1933: 392. „The nautical mile [mille marin] is in principle the length of the sexagesimal minute of a meridian at a latitude of 45°. ... If we assume that the metre is exactly the ten-millionth part of the terrestrial quarter meridian, it would be equal to 1,851.85 m.” – Translation by Wikipedia.