A Finite Lattice without Critical Triple that cannot be Embedded into the Enumerable Turing Degrees.

Steffen Lempp Manuel Lerman A Finite Lattice without Critical Triple that cannot be Embedded into the Enumerable Turing Degrees. 167-185 1997 87 Ann. Pure Appl. Logic 2 db/journals/apal/apal87.html#LemppL97