Wikipedia:Conflicting sources

Sometimes, although not often, the policy that our threshold is verifiability, not truth means that although something can only be one or another, we cannot determine which one it is. This happens, when two (or more) equally reliable sources contradict each other about certain facts. In such situation, editors need to report all significant viewpoints as fairly as possible.

Handling conflicting sources
Prefer up-to-date sources. In the case of a conflict stemming from the fact that the general or academic consensus about the subject has changed over time, the current consensus should be given preference. Older works, if referenced at all, should then be clearly distinguished as such and be used primarily to show the historical development of the subject. Be aware that sometimes older works are re-published with very minor changes, which can make their statements seem newer than they really are.

Report all significant viewpoints. If the conflict is about an interpretation of the facts rather than a simple matter of fact, and cannot be resolved by demonstrating some of the conflicting sources to be in error, in order to maintain a neutral point of view, include all significant points of view with appropriate attributions. In those cases, it is up to the reader to choose which source they want to believe personally and not the task of Wikipedia editors to choose for them. Instead, the article should contain a mention that different points of view exist. If the issue is a simple matter of fact (e.g., a birth date) but cannot be resolved, this can be reported by presenting the apparently most plausible choice in the text while adding a footnote with the alternatives.

Omit unimportant details. If the conflicting fact is of marginal encyclopedic interest, reporting on several views may lead to giving it undue prominence. A reasonable approach in that case would be to omit it entirely.

How not to handle conflicting sources

 * Do not remove the conflicting sources just because they contradict the sources already in the article.
 * Do not choose which one is "true" and discard the others as incorrect, except in the unusual instance that one source can be demonstrated to be factually erroneous (an obviously unreasonable number of digits in a number, a correction is issued by the publisher, later sources say that the information has previously been misreported, etc.).
 * Do not cite (the lack of) official announcements by the subject of the article or people related to it as a reason why a source is unreliable.