Collect. Czech. Chem. Commun.
1978, 43, 2471-2477
https://doi.org/10.1135/cccc19782471
The structure and relative and absolute configurations of the sesquiterperpenic lactones gradolide and polhovolide from Laserpitium siler L.
Miroslav Holub, Otakar Motl and Zdeněk Samek