Conflict of interest statement
The authors declare no competing interests.
Funding
The study receives no extramural funding.
Authors’ contributions
Hoang Minh Ngan was responsible for drafting the manuscript. Tran Thi Thuy conceptualized the study design and critically revised the manuscript. Tran Quang Anh and Nguyen Dinh Tao contributed to data collection and manuscript revision. Nguyen Hong Phuc conducted data processing and analysis.
Publisher’s Note
The Publisher of the Journal remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
CHANGE HISTORY
A Correction to this paper has been published:
https://doi.org
The Retraction Note was updated to reflect reception of statements of disagreement from all authors.
This article has been retracted.Please see the Retraction Notice for more detail:
https://doi.org