The 2nd order corrections to the interaction of two reggeized gluons   from the bootstrap
  The 2nd order corrections are obtained to both forward and nonforward interaction of reggeized gluons in the octet colour channel using as a basis the bootstrap relation and a specific ansatz to solve it. The obtained forward kernel coincides with the logarithmic term plus two first non-logarithmic terms in the Pomeron 2nd order kernel. Both forward and nonforward kernels are found to be infrared finite. 
Mikhail Braun and Gian Paolo Vacca