@article{10_4064_fm_47_2_219_242,
     author = {R. Montague and R. Vaught},
     title = {Natural models of set theories},
     journal = {Fundamenta Mathematicae},
     pages = {219--242},
     publisher = {mathdoc},
     volume = {47},
     number = {2},
     year = {1959},
     doi = {10.4064/fm-47-2-219-242},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-47-2-219-242/}
}