Gould, J., & Gould, E. (1838). Genus Sphenostoma, Gould. Zenodo.
Cita Chicago (17th ed.)Gould, John, i Elizabeth Gould. Genus Sphenostoma, Gould. Zenodo, 1838.
Cita MLA (9th ed.)Gould, John, i Elizabeth Gould. Genus Sphenostoma, Gould. Zenodo, 1838.
Atenció: Aquestes cites poden no estar 100% correctes.