@article(etm,

title = "Extra Theory Morphisms for Institutions:

logical semantics for multi-paradigm languages",

author = "{R\u{a}zvan} Diaconescu",

volume = 6,

number = 4,

year = 1998,

journal = "Applied Categorical Structures",

pages = "427--453",

note = "A preliminary version appeared as JAIST Technical

Report IS-RR-97-0032F in 1997.")