Correlation of lead (Pb) content towards the number of stomata on the plant Dracaena marginata tricolor in some places of Surabaya CityHamidah, Dwiyanti Putri and Hery PurnobasukiE3S Web Conf., 153 (2020) 02002DOI: https://doi.org/10.1051/e3sconf/202015302002