Kazanas, D. (1980). “Dynamics of the universe and spontaneous symmetry breaking”. Astrophys. J.241: L59–63. doi:10.1086/183361.
Einhorn, Martin B (1981). “Monopole Production In The Very Early Universe In A First Order Phase Transition”. Nucl. Phys.B180: 385–404. doi:10.1016/0550-3213(81)90057-2.
Guth, A.H. (1982). “Fluctuations in the new inflationary universe”. Phys. Rev. Lett.49: 1110–3. doi:10.1103/PhysRevLett.49.1110.