@article{paperid:1029233,
author = {Hejazian, Shirin and Mahdavian Rad, Hussein and Madjid Mirzavaziri,  and Mohammadian, Hossein},
title = {Bi-parameter Semigroups of linear operators},
journal = {Electronic Journal of Theoretical Physics},
year = {2012},
volume = {9},
number = {26},
month = {January},
issn = {1729-5254},
pages = {173--182},
			numpages = {9},
keywords = {One Parameter Semigroup; Bi-parameter Semigroup; σ-derivation; Infinitesimal generator},
}