Editorial Note
Crossref DOI link: https://doi.org/10.1007/s10677-017-9815-0
Published Online: 2017-05-25
Published Print: 2017-06
Update policy: https://doi.org/10.1007/springer_crossmark_policy
Musschenga, A. W.
Heeger, F. R.
License valid from 2017-05-25
