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IOP Science

Referencing, citation and novelty

IOP Publishing is a member of the Committee for Publication Ethics (COPE), and apply the principles of publication ethics outlined in the COPE Core Practices.


Authors have a responsibility to fully acknowledge the work of others (be it published or unpublished) that is used in their research and to cite publications that have influenced the direction and course of their study. Information obtained in private correspondence or conversation should only be used with the explicit permission of the individuals involved. Information obtained whilst providing confidential services, such as refereeing research articles or grant applications, should not be used without permission of the original author.

All sources for the article must be clearly disclosed and permissions obtained from the original authors (and original publishers if they hold the copyright) for any figures or significant extracts that are to be reproduced or quoted. Collection of such permissions is the responsibility of the authors.

References should be helpful to the reader and advance the article, so authors should ensure they are relevant, recent and easy to find.

Citation manipulation

Authors should ensure that citations add value and are not unfairly bias towards an individual, group or organisation. Only sources drawn upon in the work should be referenced, and citations should support the points which they reference.

The practice of including superfluous references to the authors own work, or the works of others, merely to promote and inflate citation scores is unethical. IOP Publishing regularly screens submissions for this practice. Any authors under pressure to include irrelevant citations should report this to


Submitted articles must be the authors’ own work, expressed in their own words. Plagiarism constitutes unethical scientific behaviour and is never acceptable. Plagiarism ranges from the unreferenced use of others’ ideas, to replication (without sufficient attribution or use of quotation marks) of sections of text from other sources, to submission of a complete paper under ‘new’ authorship. IOP Publishing routinely screens submissions for originality via iThenticate, industry standard plagiarism detection software.

Duplicate publication

Duplicate publication is the production of multiple papers with the same, or essentially the same, content by the same authors and is viewed as unacceptable. Submitted research articles must be novel and original.

In the case of articles that expand upon previously published conference proceedings, or conference write-ups that discuss work already published in an earlier paper, some limited exceptions to this rule may apply. However, in these cases authors should consult with the journal staff before submission. In all instances, articles must clearly cite their sources and present some new contribution to the published literature otherwise such articles will be rejected.

Multiple publications arising from a single research project should be clearly identified as such and the primary publication should be referenced. Translations and adaptations for different audiences should be clearly identified as such, should acknowledge the original source, and should respect relevant copyright conventions and permission requirements. If in doubt, authors should seek permission from the original publisher before republishing any work.

Text recycling

Text recycling occurs when authors publish sections of the same text in more than one of their own publications. Authors should always be clear and cite any re-used text in the manuscript, respecting relevant copyright conventions and permission requirements. Authors should state in their cover letter if there are sections of the article that have already been published elsewhere. We acknowledge there are some instances where text recycling may be acceptable, and others where it is unacceptable. All text recycling will be investigated and considered on an individual basis by our Editors.

Parallel submission

It is also unethical to submit the same, or essentially the same, article to a second primary research journal whilst it remains under active consideration by another.

To aid us in detecting any submissions that do not meet the above requirements, we regularly use plagiarism-detection software to screen articles.