1. H W Kroto, J R Heath, S C O’Brien and R F Curl Nature. 318 162 (1985)
2. M Contreras, D Avila, J Alvarez and R Rozas Struct. Chem. 21 573 (2010)
3. S Tetasang, S Keawwangchai, B Wanno and V Ruangpornvisuti Struct. Chem. 23 7 (2012)
4. A Ahmadi, J Beheshtian and N L Hadipour Phys. E. 43 1717 (2011)
5. J Beheshtian, M Kamfiroozi, Z Bagheri and A Ahmadi Phys. E. 44 546 (2011)