National Extension College Trust Ltd
| title | ISBN-13 | year of publica- tion |
|---|---|---|
| General Certificate of Secondary Education Business Studies | 978-0-86082-918-8 | 1987 |
| General Certificate of Secondary Education Law | 978-0-86082-928-7 | 1987 |
| General Certificate of Secondary Education Physics | 978-0-86082-933-1 | 1987 |
| General Certificate of Secondary Education Sociology | 978-0-86082-893-8 | 1987 |