Efficacy of Brazilian green propolis (EPP-AF®) as an adjunct treatment for hospitalized COVID-19 patients: a randomized, controlled clinical trial - Silveira, Marcelo Augusto Duarte; De Jong, David; Berretta, Andresa Aparecida; Galvão, Erica Batista dos Santos; Ribeiro, Juliana Caldas; Cerqueira-Silva, Thiago; Amorim, Thais Chaves; Conceição, Luis Filipe Miranda Rebelo da; Gomes, Marcel Miranda Dantas; Teixeira, Maurício Brito (Biomedicine & Pharmacotherapy, 2021)