On Packing Unequal Rectangles in the Unit Square. - Derek Jennings (J. Comb. Theory A, 1994)

On packings of squares and rectangles. - Derek Jennings (Discret. Math., 1995)

An extension for residue difference sets. - Derek Jennings; Kevin Byard (Discret. Math., 1997)

Qualified residue difference sets with zero. - Derek Jennings; Kevin Byard (Discret. Math., 1998)