@incollection{JEDP_1992____A12_0,
     author = {Novikov, Roman G.},
     title = {Transparent potentials and hamiltonian systems},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {12},
     pages = {1--4},
     publisher = {Ecole polytechnique},
     year = {1992},
     mrnumber = {1191919},
     zbl = {0771.35061},
     language = {en},
     url = {http://archive.numdam.org/item/JEDP_1992____A12_0/}
}