Journal of Approximation TheoryVolume 37, Issue 2, February 1983, Pages 125-136Simultaneous approximation, interpolation and Birkhoff systemsAuthor links open overlay panelR.A LorentzShow moreShareCitehttps://doi.org/10.1016/0021-9045(83)90057-6Get rights and contentUnder an Elsevier user licenseopen archivePrevious article in issueNext article in issueRecommended articlesCited by (0)Copyright © 1983 Published by Elsevier Inc.