Compression struts with nonprogressively variable moment of inertia (1938)
NASA Technical Reports Server (NTRS) · leaf 19
Fig. 5 N.A.C#A. Technical Memorandum No. 861 … Substitute moment of inertia:Jm= Jg Figure 5.- Buckling struts with non-progressively variable moment of inertia; substitute moment of inertia Jm.
NASA Technical Reports Server (NTRS)
Internet Archive · NASA Technical Reports · Public domain (US government work). Free to use for anything.