Eisold, Michael Unsaturated Four-Membered Rings: Efficient Strategies for the Construction of Cyclobutenes and Alkylidenecyclobutanes. [electronic resource] - Chemistry (Weinheim an der Bergstrasse, Germany) Jan 2017 - 1634-1644 p. digital Publication Type: Journal Article ISSN: 1521-3765 Standard No.: 10.1002/chem.201604585 doi