Bal, D. Rediscovery of the Sumatran Endemics Onychogomphus Rappardi (Odonata: Gomphidae) and Herona Sumatrana Sumatrana (Lepidoptera: Nymphalidae), With Notes on Observations of Other Rare Butterflies and Moths from the North of Sumatra. BIO PALEMBANICA 2024, 1, 48-58.