Posselt, B., Popov, S. B., Haberl, F., Trümper, J., Turolla, R., & Neuhäuser, R. (2008). The needle in the haystack: where to look for more isolated cooling neutron stars. Astronomy & Astrophysics, 482(2), 617-629. doi:10.1051/0004-6361:20078430.