All references, including URLs, must be numbered consecutively, in square brackets, in the order in which they are cited in the text, followed by any in tables or legends. Each reference must have an individual reference number. If automatic numbering systems are used, the reference numbers must be finalized and the bibliography must be fully formatted before submission.
Only articles, datasets and abstracts that have been published or are in press, or are available through public e-print/preprint servers, may be cited. Any in press articles cited within the references and necessary for the reviewers' assessment of the manuscript should be made available if requested by the editorial office. Unpublished abstracts, unpublished data and personal communications should not be included in the reference list, but may be included in the text and referred to as "unpublished observations" or "personal communications" giving the names of the involved researchers.
Obtaining permission to quote personal communications and unpublished data from the cited colleagues is the responsibility of the author.
Footnotes are not allowed, but endnotes are permitted. Journal abbreviations follow Index Medicus/MEDLINE. Citations in the reference list should include all named authors, up to the first 3 before adding 'et al.'.