The research of Mihaela A. Petric was supported by the Grant PN-II-RU-TE-2011-3-0239 of the Romanian Ministry of Education and Research. Mihaela Petric, Faculty of Sciences North University Center at Baia Mare, Technical University of Cluj-Napoca 3 September 2013 Acknowledgements The research of Mihaela A. Petric was supported by the Grant PN-II-RU-TE-2011-3-0239 of the Romanian Ministry of Education and Research. Competing interests None declared
The research of Mihaela A. Petric was supported by the Grant PN-II-RU-TE-2011-3-0239 of the Romanian Ministry of Education and Research.
3 September 2013
Acknowledgements
The research of Mihaela A. Petric was supported by the Grant PN-II-RU-TE-2011-3-0239 of the Romanian Ministry of Education and Research.
Competing interests
None declared