| Type | Article |
| Authors(s) | Pryer KM, Schneider H, Smith AR, Cranfill R, Wolf PG, Hunt JS. |
| Year | 2001 |
| Title | Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants. |
| Periodical | Nature |
| Volume | 409 |
| Page(s) | 618–621 |
| Type | Article |
| Authors(s) | Pryer KM, Schneider H, Smith AR, Cranfill R, Wolf PG, Hunt JS. |
| Year | 2001 |
| Title | Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants. |
| Periodical | Nature |
| Volume | 409 |
| Page(s) | 618–621 |