In design of timber structures the compressive strength perpendicular to the grain is important. Currently, there is no reliable model that accounts for beam size and load situations while the standardized test methods according to ASTM, ISO and CEN lead to very different strength values. In recent past, a number of models have been proposed to predict the perpendicular to grain strength. A data base that consists of 685 test results is used for the evaluation of some predicting models. It is only the model by Van der Put  that explains the different test results.
Leijten, A. J. M., Larsen, H. J., & Put, van der, T. A. C. M. (2010). Structural design for compression strength perpendicular to the grain of timber beams. Construction and Building Materials, 24(3), 252-257. https://doi.org/10.1016/j.conbuildmat.2009.08.042