[1] Alonso L., Cerf R.: 
The three dimensional polyominoes of minimal area. Electronic J. of Combin. 3 (1996), 1-39. 
MR 1410882 | 
Zbl 0885.05056[2] Bollobás B., Leader I.: 
Compressions and Isoperimetric Inequalities. J. Combin. Theory Ser. A 56 (1991), 47-62. 
MR 1082842 | 
Zbl 0731.05043[3] Bosch R. A.: A Pentomino Exclusion Problem. Mathematical Programming Newsletter, Optima 60 (december 1998), 3.
[4] Bosch R. A.: 
Peaceably Coexisting Armies of Queens. Mathematical Programming Newsletter, Optima 62 (June 1999), 3. 
MR 1244056[5] Golomb S. W.: 
Polyominoes - Puzzles, Patterns, Problems, and Packings. Princeton Science Library, 1994. 
MR 1291821 | 
Zbl 0831.05020[6] Melissen H.: Packing and Covering with Circles. PhD Thesis, Proefschrift Universiteit Utrecht, Nederland, 1997.
[7] Wang D.-L., Wang P.: 
Extremal configurations on a discrete torus and a generalization of the generalized Macaulay theorem. SIAM J. Appl. Math. 33 (1977), 55-59. 
MR 0438237 | 
Zbl 0362.05048