\bibitem{CousotCousot-MIT-79} P{.} Cousot and R{.} Cousot. \newblock Constructive Versions of Tarski's Fixpoint Theorems and Asynchronous Iterative Methods for Solving a Fixpoint System of Equations in a Chain-Complete Poset. \newblock Seminar, MIT, Cambridge, Massachusetts, USA, 25 june 1979, invited by Professor C{.} Hewitt. @unpublished{CousotCousot-MIT-79, author = {P{.} Cousot and R{.} Cousot}, title = {Constructive Versions of Tarski's Fixpoint Theorems and Asynchronous Iterative Methods for Solving a Fixpoint System of Equations in a Chain-Complete Poset}, note = {Seminar, MIT, Cambridge, Massachusetts, USA, 25 june 1979, invited by Professor C{.} Hewitt}, }