1993
Spiros Cotsakis, Georgios Flessas, Generalized No-Hair Theorems, Phys. Lett., Vol = B319, pp. = 0, , 69-73, 1993,   
Spiros Cotsakis, P. Leach, Painleve Analysis of the Mixmaster Universe, J. Phys., Vol = A27, pp. = 0, , 1625-1631, 1993,   
1991
Spiros Cotsakis, J. Barrow, Self-Regenerating Inflationary universe in higher-order gravity in arbitrary dimension, Phys. Lett., Vol = B258, pp. = 0, , 299-304, 1991,   
1989
Spiros Cotsakis, J. Barrow, Chaotic Behaviour in Higher-Order Gravity Theories, Phys. Lett., Vol = B232, pp. = 0, , 172-176, 1989,   
1988
Spiros Cotsakis, J. Barrow, Inflation and the Conformal Structure of Higher-Order Gravity Theories, Phys. Lett., Vol = B214, pp. = 0, , 515-518, 1988,