@book{191260,
	author = {Bogolubov,  Nikolai Nikolaevich  and Petrina, D. Ya.},
	title = {On a class of model systems permitting a decresse of the Hamiltonian power in the thermodynamic limit :},
	year = {1977.},
	series = {Academy of Sciences of Ukrainian SSR : Preprint},
	address = {Kiev,}
}