BioStor
 | A revision of the North American two-winged flies of the family Therevidae Frank R Cole (1923) Proceedings of The United States National Museum 62: 1-140 |
 | The flora of the Revillagigedo Islands Ivan Murray Johnston (1931) Proceedings of the California Academy of Sciences 20: 9-104 |
 | Classification of Insects. A key to the known families of insects and other terrestrial arthropods. [1st Edition] C T Brues and A L Melander (1932) Bulletin of the Museum of Comparative Zoology 73: 1-672 |
 | The separation of Trimorpha (Compositae: Astereae) from Erigeron G L Nesom (1989) Phytologia 67: 61-66 |
 | Infrageneric taxonomy of New World Erigeron (Compositae: Astereae) G L Nesom (1989) Phytologia 67: 67-93 |
 | Further definition of Conyza (Asteraceae: Astereae) G L Nesom (1990) Phytologia 68: 229-233 |
 | The Co-Radiations of Pollinating Insects and Angiosperms in the Cretaceous David Grimaldi (1999) Annals of the Missouri Botanical Garden 86: 373-406 |