@inproceedings{Goldoni:200939, author = "Goldoni, Otavio and da Silva, Maria de Fátima Alves", title = "{Energy conditions for electromagnetic field in presence of cosmological constant}", doi = "10.22323/1.081.0072", booktitle = "Proceedings of 5th International School on Field Theory and Gravitation {\textemdash} PoS(ISFTG)", year = 2009, volume = "081", pages = "072" }