Chemistry of Heterocyclic Compounds.
Латвийский институт органического синтеза Латвийской академии наук / Springer New York Consultants Bureau.
Vol. 25.
1989.
P. 301-305
The covariant, unitary and causal S-matrix for nonlocal relativistic quantum field theories is constructed. This S-matrix is based on a new notion of the covariant chronological ordering. © 1989 Società Italiana di Fisica.