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Lua i Stíl Chicago (17ú heag.)Beukers, Frits. The Generalised Ramanujan-Nagell Equation. [S.l.: s.n., 1979.
Lua MLA (8ú heag.)Beukers, Frits. The Generalised Ramanujan-Nagell Equation. s.n., 1979.
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