The contribution of off-shell gluons to the structure functions F2c and FLc and the unintegrated gluon distributions A.V. Kotikov, A.V. Lipatov, G. Parente and N.P. ZotovEur. Phys. J. C, 26 1 (2002) 51-66DOI: https://doi.org/10.1140/epjc/s2002-01036-y