@article{ZNSL_1990_184_a14,
     author = {E. L. Lehmann},
     title = {Verifiability and strong verifiability},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {182--188},
     year = {1990},
     volume = {184},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1990_184_a14/}
}