@article{10_4153_S0008439520000582,
     author = {Klyachko, Anton A.},
     title = {The {Klein} bottle group is not strongly verbally closed, though awfully close to being so},
     journal = {Canadian mathematical bulletin},
     pages = {491--497},
     year = {2021},
     volume = {64},
     number = {2},
     doi = {10.4153/S0008439520000582},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/S0008439520000582/}
}