The existence of the fourth quark-lepton generation is not excluded by the
electroweak precision data. However, the recent results on the 126 GeV higgs
boson production and decay do not allow an extra generation at least as far as
the perturbation theory can be used.Comment: Report at the conference QTHEP 2013, Repino, June 23-30 2013 and
lecture at the 2013 Helmholz School Physics of Heavy Quarks and Hadrons,
Dubna, July 15-28. An important acknowledgement is adde
