This study describes materials used by secondary school students in preparing independent study papers and other types of assignments calling for library use, including the use of home collections and school, public, college, and special libraries. Bibliometric methods were used to provide measurement of the nature and currency of books, magazines, encyclopedias, newspapers, government documents, and pamphlets referenced by students. A sample of 15 high schools representing five school districts and two independent schools provided data on 1,845 students from 73 classes. Four major sources of data were (1) bibliographies (or reference lists) of student papers; (2) a questionnaire survey of students describing facilities used; (3) a survey of teachers on assignments, instructions given students, and type of library skills provided; and (4) interviews with school librarians on user services and collection policies. Book reports were examined as a separate investigation, and a separate analysis was performed to describe lists of recommended titles included in 19 bibliographic publications used as selection tools by high school librarians. Among these tools were the Senior High School Catalog, the Junior High School Catalog, the National Association of Independent Schools list, and lists of award books. (Author/RAA)