[17] M Znojil, F Gemperle and O Mustafa, J. Phys. A : Math. Gen. 35 (2002) 5781 [18] O Mustafa and M Znojil, J. Phys. A : Math. Gen. 35 (2002) 8929 [19] B F Samsonov and P Roy, J. Phys. A : Math. Gen. 38 (2005) L249. [20] A Mostafazadeh, J. Math. Phys. 43 (2002) 2814 [21] A Mostafazadeh, Nucl.Phys. B 640 (2002) 419 [22] A Mostafazadeh, J. Math. Phys. 43 (2002) 205 [23] A Mostafazadeh, J. Math. Phys. 43 (2002) 3944 [24] A Mostafazadeh, J. Math. Phys. 44 (2003) 974 [25] A Mostafazadeh, J. Phys. A : Math. Gen. 38 (2005) 3213 [26] A Sinha and P Roy, Czech. J. Phys. 54 (2004) 129 [27] L Jiang, L Z Yi and C S Jia, Phys Lett A 345 (2005) 279 [28] B P Mandal, Mod. Phys. Lett. A 20 (2005) 655 [29] B Znojil, H B´ıla and V Jakubsky, Czech. J. Phys. 54 (2004) 1143 [30] A Mostafazadeh and A Batal, J. Phys. A : Math. Gen. 37 (2004) 11645 [31] B Bagchi and C Quesne, Phys. Lett. A 301 (2002) 173 [32] L Solombrino, J. Math. Phys. 43 (2002) 5439 [33] T V Fityo, J. Phys. A : Math. Gen. 35 (2002) 5893 [34] O Mustafa and S H Mazharimousavi, Czech. J. Phys. 56 (2006) 967 (arXiv: quant-ph/0603237) 15