2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/4313This talk introduces the contributions of the lecturers to the international summer school ``Historical Development of Modern Cosmology'' held at the Universidad Internacional Menéndez Pelayo, Valencia, Spain, during September 18-22 2000.8 pages, 3 eps figures (included in the main file) and 3 separated gif figures. Conference proceedingsAstrophysicstext