@article{MM2_1971__4_154047,
     author = {Yasutoshi Nomura},
     title = {Induced morphisms for {Lambek} invariants of commutative squares.},
     journal = {Manuscripta mathematica},
     pages = {263--276},
     publisher = {mathdoc},
     volume = {4},
     year = {1971},
     zbl = {0212.35102},
     url = {http://geodesic.mathdoc.fr/item/MM2_1971__4_154047/}
}