Despite some reported limitations, Web of Science has been the standard source to assess the impact of individual articles, and consequently journals. By analysing the citations to articles published in the field of paediatric oncology, we demonstrate that Scopus and Google Scholar, the two new citation databases, retrieve more citations than Web of Science. The strength of Scopus lies in identifying non-English literature from Western and Eastern Europe, while Google Scholar is proficient at identifying English and non-English literature from Africa, Asia and Central and South America. These findings have implications for researchers, journals and health libraries.