@book{Katok_1995,
    doi = {10.1017/cbo9780511809187},
    url = {https://doi.org/10.1017%2Fcbo9780511809187},
    year = {1995},
    month = {apr},
    publisher = {Cambridge University Press},
    author = {Anatole Katok and Boris Hasselblatt},
    title = {Introduction to the Modern Theory of Dynamical Systems}
}

@book{Katok_1995, doi = {10.1017/cbo9780511809187}, url = {https://doi.org/10.1017%2Fcbo9780511809187}, year = {1995}, month = {apr}, publisher = {Cambridge University Press}, author = {Anatole Katok and Boris Hasselblatt}, title = {Introduction to the Modern Theory of Dynamical Systems} }