The Dr. Martin Luther King, Jr. Library in San Jose, California is a unique dual-use library serving the students of San Jose State University and the community of San Jose, California. The reference collections of the two libraries are merged and interfiled to promote ease of access for both populations served. Economies of scale were realized through collaborative collection development activities for major reference purchases between the two institutions. This article describes the planning and creation of the King Library's merged reference collection and reviews the literature of collaborative collection development and merged or interfiled collections.