Não informado. (2020). Progress Report of the Bulgarian National Committee for the International Biological Programme. Bulgarian National Committee for the International Biological Programme.
Citação do estilo Chicago (17ª ed.)Não informado. Progress Report of the Bulgarian National Committee for the International Biological Programme. Sofia: Bulgarian National Committee for the International Biological Programme, 2020.
Citação MLA (8ª ed.)Não informado. Progress Report of the Bulgarian National Committee for the International Biological Programme. Bulgarian National Committee for the International Biological Programme, 2020.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.