Note on generating all subsets of a finite set with disjoint unions. Ellis, David — 2009 The Electronic Journal of Combinatorics [electronic only]
An algebraic characterization of lattices among semilattices Ellis, David — 1949 Portugaliae mathematica
On metric groupoids and their completions Conkling, Randall; Ellis, David — 1953 Portugaliae mathematica
A Modification of the Parallelogram Law Characterization of Hilbert Spaces. David Ellis Mathematische Zeitschrift
Notes on Abstract Distance Geometry. II. Implications of basality in generalized semimetric spaces. David Ellis — 1951 Monatshefte für Mathematik
Triangle-intersecting families of graphs David Ellis; Yuval Filmus; Ehud Friedgut — 2012 Journal of the European Mathematical Society