Dendrochronological research project. D.J. de Vries and H. Tisje performed the research and produced the dating resuls. Digitization of the analog measurement series: Benno Ridderhof (VU, 2008); further additions, verification and reformatting: Esther Jansma (2011, 2022).

The year in which the research stored in https://dataverse.nl/dataverse/stichtingring took place, from 1985 onwards can be found in the report number, with for example ‘P:1997001’ implying that this particular study took place in 1997. Interpretations of the most likely wood provenance and estimations of the number of missing sapwood rings, if included in the original research report, are based on the knowledge at the time and may be subject to later refinement.