. . . "Handbook of natural products data / 2, Pentacyclic triterpenoids" . . . . . . . . "Handbook of natural products data. Vol.2, Pentacyclic triterpenoids"@en . . "Handbook of natural products data. Vol. 2, Pentacyclic triterpenoids" . . "Handbook of natural products / vol. 2, Pentacyclic triterpenoids" . . . "Handbook of natural products data Vol. 2 Pentacyclic, triterpenoids" . . . "Triterpènes." . .