@article{CMA_2016_100_a4,
     author = {M. V. Shamolin},
     title = {Integrable motions of a pendulum in a two-dimensional plane},
     journal = {Contemporary Mathematics and Its Applications},
     pages = {36--57},
     year = {2016},
     volume = {100},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMA_2016_100_a4/}
}