Over time Stern expanded his specialties to include Latin American art, particularly that of Mexican painter and muralist Alfredo Ramos Martínez, who is considered by many to be the "Father of Mexican Modernism". Stern founded the Alfredo Ramos Martínez Research Project to promote and protect the legacy of the artist. He serves as the Director of the Project, which is currently compiling the catalogue raisonné for Ramos Martínez. Stern’s advocacy reestablished the reputation of Ramos Martínez, resulting in a major retrospective at the Museo Nacional de Arte (MUNAL) in Mexico City in 1992.
