One or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Aphanite". Encyclopædia Britannica. Vol. 2 (11th ed.). Cambridge University Press. p. 163. /wiki/Public_domain
Bates and Jackson (1984). Dictionary of Geological Terms (3rd ed.). American Geological Institute. /wiki/American_Geological_Institute
One or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Aphanite". Encyclopædia Britannica. Vol. 2 (11th ed.). Cambridge University Press. p. 163. /wiki/Public_domain