Could anybody suggest a reference for the present stellar models? In particular, I would appreciate references containing the core temperatures and pressures of neutron stars...
I would suggest Stellar Structure and Evolution by Rudolf Kippenhahn and Alfred Weigert. It's a pretty thorough reference guide in terms of describing the processes that occur in stars and how they are used in stellar models. It's also cited quite a bit in astrophysics papers which deal with computational models of stars. It includes a brief chapter on neutron stars which gives some of what you might be seeking.
For more recent and accurate values for these core temperatures and pressures, I would search for astrophysics papers that deal with neutron star evolution. A simple keyword search for "neutron star" or "neutron star structure" in an academic journal database should return an ample amount of results from various papers including tables, graphs and other useful figures.