According to Wikipedia's general notability guideline, a topic is presumed to be notable if it has received significant coverage in reliable secondary sources that are independent of the subject.

Following this guideline, a subject for which only one source can be cited is unlikely to merit a standalone article.

Remember however, notability criteria consider whether sufficient sources exist, not merely how many have already been cited in the current version of the article, i.e., "can be cited" is not the same as "is cited". Therefore, rather than judging a single-source article nonnotable and listing it for deletion, please add the template {{onesource}} at the top of the article, so that someone may remedy the issue.

For single-source sections, the template {{onesource|section_name}} can be added, if you think that only one source is not enough for it.

In addition to notability, single-source articles may suffer from other problems.

• Copyright violations: If an article has just one source, it may be an exact copy of the source provided, or a derivative work of that source, and therefore a copyright violation; mere paraphrasing, without sufficient originality, may not be enough to avoid copyright infringement. Under the doctrine of substantial similarity, a work can be found to infringe copyright even if the wording of text has been changed. Wikipedia's Copyright FAQ recommends using multiple sources to avoid substantial similarity infringement.

Any such articles that are not copyright violations (for example, because the infringed source is in the public domain) may still constitute plagiarism.

• Original research: Information in a single-sourced article beyond what is drawn from its lone source is likely original research – facts and ideas not already published by reliable sources.

• Dictionary definitions: Wikipedia is not a dictionary. Under no circumstances can an article be supported solely by a dictionary entry.

Lone source published by the article's subject[edit]

Some of the least permissible articles are those whose lone source cited is published by the article's subject. This constitutes a conflict of interest. Any company, organization, group, or individual interest has the ability to publish promotional material about itself. Such self-published sources do not demonstrate that people independent of the subject consider it notable enough to be worthy of attention. Therefore, self-published sources cannot be used to establish notability. At the same time, non-promotional information of non-controversial validity may be taken from a self-published source after notability has been established.

An article that relies entirely on information from the subject itself may be deleted, possibly under speedy deletion criteria G11, if reasonable search shows independent sources..