Use of minute duckweed (Lemna perpusilla) for supplemental feed in catfish (Clarias sp.) culture: determination of the optimal proportion using powersim simulationTjandra Chrismadha, Livia Rossila Tanjung and SutrisnoE3S Web Conf., 322 (2021) 02015DOI: https://doi.org/10.1051/e3sconf/202132202015