Hellers, B. G. (1973). Columns with and without tensile strength: An extension of theories used for the comparison of deflections, rotations, stresses and stability. National Swedish Institute for Building Research.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Hellers, Bo Göran. Columns with and Without Tensile Strength: An Extension of Theories Used for the Comparison of Deflections, Rotations, Stresses and Stability. Stockholm: National Swedish Institute for Building Research, 1973.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Hellers, Bo Göran. Columns with and Without Tensile Strength: An Extension of Theories Used for the Comparison of Deflections, Rotations, Stresses and Stability. National Swedish Institute for Building Research, 1973.
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