Não informado. (2008). School bell. National School Public Relations Association.
Citação do estilo Chicago (17ª ed.)Não informado. School Bell. Washington: National School Public Relations Association, 2008.
Citação MLA (8ª ed.)Não informado. School Bell. National School Public Relations Association, 2008.
警告：这些引文格式不一定是100％准确.