Wazwaz, Abdul-Majid. "Two integrable extensions of the Kadomtsev-Petviashvili equation" Open Physics, vol. 9, no. 1, 2011, pp. 49-56. https://doi.org/10.2478/s11534-010-0056-2
Wazwaz, A. (2011) Two integrable extensions of the Kadomtsev-Petviashvili equation. Open Physics, Vol. 9 (Issue 1), pp. 49-56. https://doi.org/10.2478/s11534-010-0056-2
Wazwaz, Abdul-Majid. "Two integrable extensions of the Kadomtsev-Petviashvili equation" Open Physics 9, no. 1 (2011): 49-56. https://doi.org/10.2478/s11534-010-0056-2