[1] Netto E.:
Lehrbuch der Combinatorik. Zweite Aufl., Bеrlin 1927. Rеprint Nеw York 1958.
MR 0095126
[2] Peltesohn R.:
Kine Lösung der beiden Heffterschen Differenzenprobleme. Compositio Math. 6 (1939) 251-257.
MR 1557027
[3] Skolem Th.:
On certain distributions of integers in pairs with given differences. Math. Seand. 5 (1957) 57-68.
MR 0092797 |
Zbl 0084.04304
[4] Skolem Th.:
Some remarks on the triple systems of Steiner. Math. Seand. 6 (1958) 273-280.
MR 0106852 |
Zbl 0105.25002
[5] O'Kееfе E. S.:
Verification of a conjecture of Th. Skolem. Math. Seand. 9 (1961) 80-82.
MR 0125024