Helmut Sies
![thumb](https://upload.wikimedia.org/wikipedia/commons/e/e2/Sies.photo.2.jpg)
1
Published: 1993
Superior document: Vorträge / Rheinisch-Westfälische Akademie der Wissenschaften : N, Natur-, Ingenieur- und Wirtschaftswissenschaften 399
2
Published: [2011]
Superior document: Title is part of eBook package: De Gruyter DGBA Reference Works <1990
Links: Get full text; Get full text; Cover