@article{JGG_2021_25_1_JGG_2021_25_1_a5,
     author = {T. Q. Hung and N. T. T. Duong },
     title = {Generalizations of {Fagnano's} {Problem}},
     journal = {Journal for geometry and graphics},
     pages = {61--69},
     year = {2021},
     volume = {25},
     number = {1},
     url = {http://geodesic.mathdoc.fr/item/JGG_2021_25_1_JGG_2021_25_1_a5/}
}