Expression of concern: “Linear manipulator: Motion control of an n-link robotic arm mounted on a mobile slider” [Heliyon 9 (2023) e12867]

An investigation conducted on behalf of the journal by Elsevier's Research Integrity & Publishing Ethics team found a significant number of citations to papers published by the authors (Sandeep Ameet Kumar, Ravinesh Chand, Ronal Pranil Chand and Bibhya Sharma) in the article. In summary, 23 papers by the authors were cited in the article since the first submission, including 14 articles by Sandeep Ameet Kumar; 13 articles by Bibhya Sharma, 3 articles by Ravinesh Chand and 3 articles by Ronal Pranil Chand, some of the cited articles are co-authored by multiple authors of this article.