When using their referencing skills, students use three types of knowledge: 1- technical knowledge, such as the use of bibliographic data management software, 2- procedural knowledge, such as problem-solving and 3- attitudinal knowledge, such as self-efficacy. This study explores the link between referencing skills, these knowledges and the number of academic years completed by students. The results of a questionnaire from 810 Quebec students show that those who begin their university studies are less efficient and less confident in their referencing skills and have less technical knowledge with bibliographic data management software than those who have studied for a longer time. All students have procedural knowledge for solving problems when using their referencing skills.