Franzen, Volker Max Planck Institute for Medical Research, Max Planck Society;
http://onlinelibrary.wiley.com/doi/10.1002/jlac.19586140105/epdf (Any fulltext)
https://dx.doi.org/10.1002/jlac.19586140105 (Any fulltext)
Franzen, V. (1958). Untersuchungen über Carbene II. Zur Existenz von Acetylenoxyden. Liebigs Annalen der Chemie, 614(1), 31-36. doi:10.1002/jlac.19586140105.