Choremi-Papadopoulou, H Panagiotou, N Samouilidou, E and Kontopidou, F Viglis, V Antoniadou, A Kosmidis, J and Kordossis, T, CD28 costimulation and CD28 expression in T lymphocyte subsets in HIV-1
infection with and without progression to AIDS, Clinical and Experimental Immunology, (119), 499-506, 2000, Blackwell Science Ltd Oxford, UK,