This study found that there were statistically significant differences in citation use and grades between students who took a library credit course and students who did not. The results of independent samples t-tests indicated that the student group that took a library credit course cited more scholarly resources, produced fewer incomplete citations, and received higher grades for its papers and courses. The data included 836 citations produced by 120 student papers and the students' grades for their papers and courses in the fall of 2004. Additionally, the survey results revealed that the students' acquisition of bibliographic research and citation skills was directly attributable to the library credit course, whereas their counterparts tended to rely on informal sources. The evidence supports the lasting impact of a library credit course on student learning. (Contains 3 tables and 35 notes.)