1. 불 대수 수리 논리학 (기호 논리학) 불 함수 논리 회로 Shannon, Claude (1938) "The Symbolic Analysis of Relay and Switching Circuits".

His work was later cited and elaborated on in Claude Shannon's seminal 1938 paper "A Symbolic Analysis of Relay and Switching Circuits".

2. 한층 더 후에는 논리학 연구의 새로운 국면이 일어나 오고, 새로운 논리학적·의미론적 이론이 발전했다.

Later, new departments of logical enquiry arose, and new logical and semantic notions were developed.

3. 1951년에 쓰여진 루카쉐비치의 책 Aristotle's Syllogistic from the Standpoint of Modern Formal Logic에서, 그는 그의 표기법의 원칙은 괄호를 피하기 위해 인자 앞에 함수적 술어를 쓰는 것이었으며, 1929년부터 그의 논리학 논문에서 그의 표기법을 사용해 왔다고 언급한다.

In Łukasiewicz's 1951 book, Aristotle's Syllogistic from the Standpoint of Modern Formal Logic, he mentions that the principle of his notation was to write the functors before the arguments to avoid brackets and that he had employed his notation in his logical papers since 1929.