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
Schmollinger J. Easing the journey back home. Nature. 2002 Mar;416(6879):5.
A journal article with 2 authors
Long F, Shi H. Simple and compact optode for real-time in-situ temperature detection in very small samples. Sci Rep. 2014 May;4:5009.
A journal article with 3 authors
Seoane J, Le H-V, Massagué J. Myc suppression of the p21(Cip1) Cdk inhibitor influences the outcome of the p53 response to DNA damage. Nature. 2002 Oct;419(6908):729–34.
A journal article with 7 or more authors
Chang C, Holtzman DA, Chau S, Chickering T, Woolf EA, Holmgren LM, et al. Twisted gastrulation can function as a BMP antagonist. Nature. 2001 Mar;410(6827):483–7.

Books and book chapters

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

An authored book
Chen X, Parini CG, Collins B, Yao Y, Ur Rehman M. Antennas for Global Navigation Satellite Systems. Chichester, UK: John Wiley & Sons, Ltd; 2012.
An edited book
Cancès E. Méthodes mathématiques en chimie quantique Une introduction. Berlin, Heidelberg: Springer; 2006.
A chapter in an edited book
Vilanova JC, Roca M, Baleato S. Bone Marrow. In: Vilanova JC, editor. Learning Musculoskeletal Imaging. Berlin, Heidelberg: Springer; 2010; pp 67–88.

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
Davis J. This Fish Has An Unusual Way To Protect Against Sperm-Spraying Cheats [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. Opportunities for Improving Program Planning for Photovoltaic Research and Development. Washington, DC: U.S. Government Printing Office; 1979.

Theses and dissertations

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

Doctoral dissertation
Vidal EM. Alcohol disorder with hip or knee surgery: Postoperative alcohol disorder-related costs and length of stay. 2014

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
Verghese A. Baby Steps. New York Times. 2017 Jun;BR16.

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