@unpublished{andre:hal-02406072,
TITLE = {ELEMENTARY SUBGROUPS OF VIRTUALLY FREE GROUPS},
AUTHOR = {Andr{\'e},
Simon},
URL = {https://hal.science/hal-02406072},
NOTE = {19 pages.},
YEAR = {2019},
MONTH = Dec, PDF = {https://hal.science/hal-02406072/file/Elementary%20subgroups%20of%20virtually%20free%20groups.pdf},
HAL_ID = {hal-02406072},
HAL_VERSION = {v1},
}