Thompson, Amy, Wickes, Alexander, Swearngin, Joe, and Bouwmeester, Dirk. Classification of electromagnetic and gravitational hopfions by algebraic type. Journal of Physics A: Mathematical and Theoretical 48.20 Web. doi:10.1088/1751-8113/48/20/205202.

Thompson, Amy, Wickes, Alexander, Swearngin, Joe, & Bouwmeester, Dirk. Classification of electromagnetic and gravitational hopfions by algebraic type. Journal of Physics A: Mathematical and Theoretical, 48 (20). https://doi.org/10.1088/1751-8113/48/20/205202

Thompson, Amy, Wickes, Alexander, Swearngin, Joe, and Bouwmeester, Dirk. "Classification of electromagnetic and gravitational hopfions by algebraic type". Journal of Physics A: Mathematical and Theoretical 48 (20). Country unknown/Code not available: IOP Publishing. https://doi.org/10.1088/1751-8113/48/20/205202. https://par.nsf.gov/biblio/10014475.

@article{osti_10014475,
place = {Country unknown/Code not available}, title = {Classification of electromagnetic and gravitational hopfions by algebraic type}, url = {https://par.nsf.gov/biblio/10014475}, DOI = {10.1088/1751-8113/48/20/205202}, abstractNote = {Not Available}, journal = {Journal of Physics A: Mathematical and Theoretical}, volume = {48}, number = {20}, publisher = {IOP Publishing}, author = {Thompson, Amy and Wickes, Alexander and Swearngin, Joe and Bouwmeester, Dirk}, }