Kenta Noguchi. Optimal 1-planar graphs which quadrangulate other surfaces. Australasian J. Combinatorics, 69:169, 2017. [doi]
@article{Noguchi17-0, title = {Optimal 1-planar graphs which quadrangulate other surfaces}, author = {Kenta Noguchi}, year = {2017}, url = {http://ajc.maths.uq.edu.au/pdf/69/ajc_v69_p169.pdf}, researchr = {https://researchr.org/publication/Noguchi17-0}, cites = {0}, citedby = {0}, journal = {Australasian J. Combinatorics}, volume = {69}, pages = {169}, }