What the ESA (Ecological Society of America) currently advises authors:
References General Formatting
● Use Chicago Style Manual “AUTHOR-DATE” citation style. Please note that final styling is applied by the publisher, and that the final style used in publication deviates slightly from what many citation services will output as Chicago Style.
● All references must contain complete information.
● Each reference in the text must have a matching citation in the reference list and vice versa.
● Only references cited in the Main Document should appear in the References section in the Main Document. References cited only in an appendix should be listed in a References section for the appendix and not included in the References section in the Main Document.
What is allowed as a citation?
The References section of a manuscript may refer only to permanently archived material. If a reasonably diligent scholar 20 years in the future could not be assured of finding a particular source, it should not be listed in the References section. Some Internet sources have a short half-life; material should only be included as formal citations if there is reasonable expectation of future availability. As a general rule, any publication that has an ISSN or ISBN is acceptable but should be referenced by name (the URL may be added, but is not essential). 1