Reference works make excellent starting points for research; they provide concise articles on key topics by scholars of the field, often accompanied by suggestions for further reading.The following are available online through the Penn Library website.
Vista panoramica desde la Alameda Central. https://commons.wikimedia.org/wiki/Mexico_City_Alameda_Central#/media/File:VISTA_PANORAMICA_DESDE_LA_ALAMEDA_CENTRAL.jpg
Most of the resources listed below are print volumes shelved in the Van Pelt Library Reference Stacks on the first floor of Van Pelt.