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.
Atenció: Aquestes cites poden no estar 100% correctes.