| year of publication | ISBN | author(s) | title |
|---|---|---|---|
| 1990 | 978-1-873160-01-5 | National Rivers Authority | Adroddiad Achyfrifon Blynyddol 1989-90 |
| 1993 | 978-1-873160-55-8 | Water pollution incidents in England and Wales, 1992: Report of the National Rivers Authority (Water quality series) | |