1. J. Weitkamp, A. Raichle, Y. Traa, M. Rupp, and F. Fuder, Chem. Commun., No. 5, 403 (2000).
2. W. R. True, Oil Gas J., Jul. 2, 78 (2012).
3. R. G. Craig, S. J. Penny, and W. A. Schwartz, Oil Gas J., Tech. 81, 161 (1983).
4. Oil Gas J., Jan. 14, 15 (2013).
5. V. S. Arutyunov and O. V. Krylov, Russ. Chem. Rev. 74, 1111 (2005).