How to format your references using the Ophthalmologica Extra citation style

This is a short guide how to format citations and the bibliography in a manuscript for Ophthalmologica Extra. For a complete guide how to prepare your manuscript refer to the journal's instructions to authors.

Using reference management software

Typically you don't format your citations and bibliography by hand. The easiest way is to use a reference manager:

PaperpileThe citation style is built in and you can choose it in Settings > Citation Style or Paperpile > Citation Style in Google Docs.
EndNoteFind the style here: output styles overview
Mendeley, Zotero, Papers, and othersThe style is either built in or you can download a CSL file that is supported by most references management programs.
BibTeXBibTeX syles are usually part of a LaTeX template. Check the instructions to authors if the publisher offers a LaTeX template for this journal.

Journal articles

Those examples are references to articles in scholarly journals and how they are supposed to appear in your bibliography.

Not all journals organize their published articles in volumes and issues, so these fields are optional. Some electronic journals do not provide a page range, but instead list an article identifier. In a case like this it's safe to use the article identifier instead of the page range.

A journal article with 1 author
Kolber ZS. Ecology. Getting a better picture of the ocean’s nitrogen budget. Science. 2006 Jun;312(5779):1479–80.
A journal article with 2 authors
Zimbelman JR, Scheidt SP. Hesperian age for western Medusae Fossae Formation, Mars. Science. 2012 Jun;336(6089):1683.
A journal article with 3 authors
Debayle E, Kennett B, Priestley K. Global azimuthal seismic anisotropy and the unique plate-motion deformation of Australia. Nature. 2005 Feb;433(7025):509–12.
A journal article with 7 or more authors
Shima S, Pilak O, Vogt S, Schick M, Stagni MS, Meyer-Klaucke W, et al. The crystal structure of [Fe]-hydrogenase reveals the geometry of the active site. Science. 2008 Jul;321(5888):572–5.

Books and book chapters

Here are examples of references for authored and edited books as well as book chapters.

An authored book
Black R. Pragmatic Software Testing. Indianapolis, Indiana: John Wiley & Sons, Inc.; 2016.
An edited book
Viamontes GF. Quantum Circuit Simulation. Dordrecht: Springer Netherlands; 2009.
A chapter in an edited book
Cao D. Legal Speech Acts as Intersubjective Communicative Action. In: Werner W, Cao D, editors. Interpretation, Law and the Construction of Meaning: Collected Papers on Legal Interpretation in Theory, Adjudication and Political Practice. Dordrecht: Springer Netherlands; 2007; pp 65–82.

Web sites

Sometimes references to web sites should appear directly in the text rather than in the bibliography. Refer to the Instructions to authors for Ophthalmologica Extra.

Blog post
Carpineti A. Scientist Have Built A Reprogrammable Quantum Computer [Internet]. IFLScience. 2016 Aug


This example shows the general structure used for government reports, technical reports, and scientific reports. If you can't locate the report number then it might be better to cite the report as a book. For reports it is usually not individual people that are credited as authors, but a governmental department or agency like "U. S. Food and Drug Administration" or "National Cancer Institute".

Government report
Government Accountability Office. Applying Agreed-Upon Procedures: Airport and Airway Trust Fund Excise Taxes. Washington, DC: U.S. Government Printing Office; 2007.

Theses and dissertations

Theses including Ph.D. dissertations, Master's theses or Bachelor theses follow the basic format outlined below.

Doctoral dissertation
Ghafoori HD. Working with Muslim children and families: A training program for child welfare social workers. 2010

News paper articles

Unlike scholarly journals, news papers do not usually have a volume and issue number. Instead, the full date and page number is required for a correct reference.

New York Times article
Pilon M. Fire Survivor and a Possible Olympian: A Horse Named Neville. New York Times. 2012 Jan;A1.

In-text citations

References should be cited in the text by sequential numbers in square brackets:

This sentence cites one reference [1].
This sentence cites two references [1,2].
This sentence cites four references [1–4].

About the journal

Full journal titleOphthalmologica Extra
ISSN (online)2296-1445

Other styles