If the lich has been defeated and his phylactery destroyed at the same time or before his body was reconstructed (http://paizo.com/threads/rzs2l7ns&page=762?Ask-James-Jacobs-ALL-your-Questions-Here#38094) i.e the liche is truly destroyed, can it be resurrected afterwards?
Relevant SRD :
Rejuvenation (Su): When a lich is destroyed, its phylactery (which is generally hidden by the lich in a safe place far from where it chooses to dwell) immediately begins to rebuild the undead spellcaster's body nearby. This process takes 1d10 days—if the body is destroyed before that time passes, the phylactery merely starts the process anew. After this time passes, the lich wakens fully healed (albeit without any gear it left behind on its old body), usually with a burning need for revenge against those who previously destroyed it.
Since the lich is an undead creature, I'm a right that they can't be ressurected?
School conjuration (healing); Level cleric 9
Casting Time: 10 minutes
Components V, S, M, DF (diamond worth 25,000 gp)
This spell functions like raise dead, except that you can resurrect a creature that has been dead for as long as 10 years per caster level. This spell can even bring back creatures whose bodies have been destroyed, provided that you unambiguously identify the deceased in some fashion (reciting the deceased's time and place of birth or death is the most common method).
Upon completion of the spell, the creature is immediately restored to full hit points, vigor, and health, with no negative levels (or Constitution points) and all of the prepared spells possessed by the creature when it died.
You can revive someone killed by a death effect or someone who has been turned into an undead creature and then destroyed. This spell can also resurrect elementals or outsiders, but it can't resurrect constructs or undead creatures.
Even true resurrection can't restore to life a creature who has died of old age.