Fort, 1958, Minimal Covering of Pairs by Triples, Pacific J. Math., 8, 709, 10.2140/pjm.1958.8.709
Hanani, 1966, A Note on Steiner Triple Systems, Math. Scand., 8, 154, 10.7146/math.scand.a-10603
Johnson, 1962, A New Upper Bound for Error Correcting Codes, IRE Trans. Information Theory, IT-8, 202
Riess, 1859, Über eine Steinerische combinatorische Aufgabe welche im 45sten Bande dieses Journal Seite 181, gestellt worden ist, J. reine angew. Math., 56, 326, 10.1515/crll.1859.56.326
Schönheim, 1964, On Coverings, Pacific J. Math., 14, 1405, 10.2140/pjm.1964.14.1405
Skolem, 1957, On Certain Distributions of Integers in Pairs with Given Differences, Math. Scand., 5, 57, 10.7146/math.scand.a-10490
Skolem, 1958, Some Remarks on the Triple Systems of Steiner, Math. Scand., 6, 273, 10.7146/math.scand.a-10551