•Seminal research is often taken for granted and not cited
•Small/niche research field
•Bias towards older, more established researchers (i.e. those publishing over a longer period)
•Incomplete and uneven coverage of citation indexes (across disciplines, publication types and languages)
•Negative citation
•Non-unique and inconsistent author names
•Incorrect citing of sources
Differences in citation patterns (by material type)
Differences in citation patterns (by discipline)
Differences in citation patterns (over time)