INDENYL AND FLUORENYL TRANSITION METAL COMPLEXES. IV. REACTIONS OF 2- AND 4-AZAFLUORENES WITH CHROMIUM HEXACARBONYL Article Thoma T., Pleshakov V.G., Prostakov N.S., Ustynyuk Yu.A., Nesmeyanov A.N., Ustynyuk N.A. Journal of Organometallic Chemistry. Vol. 192. 1980. P. 359-365