Huang F., Guo W., Structural and mechanical properties of the spines from Echinocactus grusonii cactus, Journal of Materials Science, 2013, 48(16):5420-5428, doi: 10.1007/s10853-013-7335-4
Microscopy, X-ray microanalysis, nanoindentation and spine tensile tests. The paper describes fibre organisation, the dependence of properties on measurement direction and differences between fresh and dry material. The abstract was accessible.