Citation
If you publish research that uses circlator you have to cite it as follows:
Hunt, M., Silva, N. D., Otto, T. D., Parkhill, J., Keane, J. A., & Harris, S. R. (2015). Circlator: Automated circularization of genome assemblies using long sequencing reads. Genome Biology, 16(1), 294. https://doi.org/10.1186/s13059-015-0849-0