Помогите, пожалуйста со статьей:
Collection of Czechoslovak Chemical Communications
Vladimír Pouzar, Dalibor Sameš and Miroslav Havel
1990, Volume 55, Issue 2, pp 499-511
Preparation of selectively protected derivatives of 21-nor-5-pregnene-3β,20-diol
- DOI:
http://dx.doi.org/10.1135/cccc19900499
