@article{TAC_1995_1_a7,
     author = {F. Piessens and E. Steegmans},
     title = {Categorical {Data-Specifications}},
     journal = {Theory and applications of categories},
     pages = {156--173},
     publisher = {mathdoc},
     volume = {1},
     year = {1995},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_1995_1_a7/}
}