Bergmann, Gustav (1929). “Zur Axiomatic der Elementargeometrie”. 《Monatschrift für Mathematik und Physik》 (독일어) 36 (1): 269-284. doi:10.1007/BF02307616. ISSN0026-9255. MR1549684.
Huntington, Edward V. (1933). “New sets of independent postulates for the algebra of logic, with special reference to Whitehead and Russell’s Principia mathematica”. 《Transactions of the American Mathematical Society》 (영어) 35 (1): 274–304. doi:10.1090/S0002-9947-1933-1501684-X. ISSN0002-9947. MR1501684.
Bergmann, Gustav (1929). “Zur Axiomatic der Elementargeometrie”. 《Monatschrift für Mathematik und Physik》 (독일어) 36 (1): 269-284. doi:10.1007/BF02307616. ISSN0026-9255. MR1549684.
Huntington, Edward V. (1933). “New sets of independent postulates for the algebra of logic, with special reference to Whitehead and Russell’s Principia mathematica”. 《Transactions of the American Mathematical Society》 (영어) 35 (1): 274–304. doi:10.1090/S0002-9947-1933-1501684-X. ISSN0002-9947. MR1501684.
Bergmann, Gustav (1929). “Zur Axiomatic der Elementargeometrie”. 《Monatschrift für Mathematik und Physik》 (독일어) 36 (1): 269-284. doi:10.1007/BF02307616. ISSN0026-9255. MR1549684.
Szabo, M. E. (1974). “A categorical characterization of Boolean algebras”. 《Algebra Universalis》 (영어) 4 (1): 192–194. doi:10.1007/BF02485724. ISSN0002-5240.
Huntington, Edward V. (1933). “New sets of independent postulates for the algebra of logic, with special reference to Whitehead and Russell’s Principia mathematica”. 《Transactions of the American Mathematical Society》 (영어) 35 (1): 274–304. doi:10.1090/S0002-9947-1933-1501684-X. ISSN0002-9947. MR1501684.