@article{MAN_1972__196_162243,
     author = {R. Routley},
     title = {A {Semantical} {Analysis} of {Implicational} {System} {I} and of the {First} {Degree} of {Entailment.}},
     journal = {Mathematische Annalen},
     pages = {58--84},
     publisher = {mathdoc},
     volume = {196},
     year = {1972},
     zbl = {0255.02017},
     url = {http://geodesic.mathdoc.fr/item/MAN_1972__196_162243/}
}