Collect. Czech. Chem. Commun.
1978, 43, 2444-2470
https://doi.org/10.1135/cccc19782444
11-Hydroxy-1βH,5βH,6αH,7αH-guaian-6,12-olides: Relative and absolute configuration of the sesquiterpenic lactones montanolide, isomontanolide, acetylisomontanolide and related substances
Miroslav Holub, Zdeněk Samek, Soňa Vašíčková and Milena Masojídková