@article{ZNSL_2003_300_a26,
     author = {D. Yu. Volkov},
     title = {The {Andronov--Hopf} bifurcation with~$2:1$ resonance},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {259--265},
     publisher = {mathdoc},
     volume = {300},
     year = {2003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2003_300_a26/}
}