MathSciNet bibliographic data MR560490 03B45 Ursini, Aldo A modal calculus analogous to ${\rm K}4{\rm W}$${\rm K}4{\rm W}$, based on intuitionistic propositional logic. I. Studia Logica 38 (1979), no. 3, 297–311. Article

For users without a MathSciNet license , Relay Station allows linking from MR numbers in online mathematical literature directly to electronic journals and original articles. Subscribers receive the added value of full MathSciNet reviews.