@article {Agrachev2017,
	title = {Homotopically invisible singular curves},
	journal = {Calculus of Variations and Partial Differential Equations},
	volume = {56},
	number = {4},
	year = {2017},
	month = {Jul},
	pages = {105},
	issn = {1432-0835},
	doi = {10.1007/s00526-017-1203-z},
	url = {https://doi.org/10.1007/s00526-017-1203-z},
	author = {Andrei A. Agrachev and Francesco Boarotto and Antonio Lerario}
}
