When you are using other authors’ ideas and information in your own understanding and in your own words, paraphrasing them, you need to clearly indicate the source where that specific idea/piece of information initially appears. It is important to know that this is also an important aspect of the academic research and writing.

CHERTOFF, M., 2020, Establishing Norms in Cyberspace, available at: Establishing Norm in Cyberspace
MELISSEN, J., 2013. Public Diplomacy, in: Andrew F. COOPER, Jorge HEINE, and Ramesh THAKUR, (eds.), 2013, The Oxford Handbook of Modern Diplomacy, Oxford University Press

For more practical examples, please refer to:
APA Format Citation Guide