The ECO Program Construction System: Ways of Increasing its Representational Power and Their Effects on the User Interface.

David Stuart Robertson Alan Bundy Michael Uschold Robert Muetzelfeldt The ECO Program Construction System: Ways of Increasing its Representational Power and Their Effects on the User Interface. 1-26 1989 31 International Journal of Man-Machine Studies 1 db/journals/ijmms/ijmms31.html#RobertsonBUM89