There are many common tools that can be added in integrating the concept of green accounting with green marketing, which works to achieve a new competitive advantage, especially in the field of cost reduction, quality and price competition.
In my opinion every subject that intrinsically has a green aspect can be very novel and fill the linkages of literature. In addition to this it can give a very strong competitive advantages to organizations.
Muna, you can merge and linking the green aspect even with other functional areas~a strategic fit perspective is leading to competitive advantage.
My suggestion is to Focus on strategic fit perspective~ a close fit between green accounting and green marketing strategies will lead to cost leadership~a competitive strategy.
Cost leadership is the one of the competitive strategies, you can try to link green accounting and green marketing in this way. What about sustainable competitive advantages? Here you can also find link between accounting and marketing