Thornton, Stephen. Karl Popper. Zalta, Edward N. (编). The Stanford Encyclopedia of Philosophy Summer 2017. Metaphysics Research Lab, Stanford University. 2017 [2024-08-06]. (原始内容存档于2019-03-18).
Thornton, Stephen. Karl Popper. Zalta, Edward N. (编). The Stanford Encyclopedia of Philosophy Summer 2017. Metaphysics Research Lab, Stanford University. 2017 [2024-08-06]. (原始内容存档于2019-03-18).