This guide is not an exhaustive list of resources, but it is designed to provide you with a jumping off point for further research. Consult with your professor and with me if you are struggling to find appropriate primary and secondary sources for your projects.
Bronze Ritual Bell, 1200s. Korea, Goryeo period (918-1392). Cast bronze with incised inscription; diameter: 14 cm (5 1/2 in.); overall: 22.6 cm (8 7/8 in.). The Cleveland Museum of Art, John L. Severance Fund 1992.118. Internet Archive. https://archive.org/details/clevelandart-1992.118-bronze-ritual-bell.