题目：Carbon-13 nuclear magnetic resonance spectroscopy of naturally-occurring substances- LVII† Triterpenes related to lupane and hopane
作者：Ernest Wenkert, G. Vernon Baddeley, Ivor R. Burfitt, Louis N. Moreno
期刊：Organic Magnetic Resonance
期卷页：Volume 11, Issue 7, pages 337–343, July 1978