Ambos-Spies, K., & Shore, R. A. (1993). Undecidability and 1-types in the recursively enumerable degrees. Annals of pure and applied logic, 63(1), . https://doi.org/10.1016/0168-0072(93)90206-S
Chicago Style (17th ed.) CitationAmbos-Spies, Klaus, and Richard A. Shore. "Undecidability and 1-types in the Recursively Enumerable Degrees." Annals of Pure and Applied Logic 63, no. 1 (1993). https://doi.org/10.1016/0168-0072(93)90206-S.
MLA (9th ed.) CitationAmbos-Spies, Klaus, and Richard A. Shore. "Undecidability and 1-types in the Recursively Enumerable Degrees." Annals of Pure and Applied Logic, vol. 63, no. 1, 1993, https://doi.org/10.1016/0168-0072(93)90206-S.
Warning: These citations may not always be 100% accurate.