On definite quadratic forms, which are not the sum of two definite or semi-definite forms

Wydawnictwa / Czasopisma IMPAN / Acta Arithmetica / Wszystkie zeszyty

Paul Erdös, Chao Ko Acta Arithmetica 3 (1939), 102-122 DOI: 10.4064/aa-3-1-102-122