Online toegang naar https://www.sciencedirect.com/science/link?ref_val_fmt=info:ofi/fmt:kev:mtx:journal&svc_val_fmt=info:ofi/fmt:kev:mtx:sch_srv&rfr_dat=saltver:1&rfr_dat=origin:ONECATE&ctx_enc=info:ofi/enc:UTF-8&ctx_ver=Z39.88-2004&rft.issn=00219797&rft.volume=429&rft.spage=34&rfr_dat=md5:ca4c14b4e43aa744e55a3ec5a3949717
