Original:  From the General System Theory is defined by Von Bertalaffy (a system complex of interacting elements), Katz and Kahn (1978) apply the concept  Open System Theory (OST) looks at the relationship between URLanizations and the environment in which they  involved.
Revised:  From the General System Theory defined by Von Bertalaffy (a system complex of interacting elements), Katz and Kahn (1978) apply the concept Open System Theory (OST) looks at the relationship between URLanizations and the environment in which they involved.
Edit intent: clarity