| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| ICTR 2019 - Proceedings of the 2nd International Conference on Tourism Research | 978-1-912764-13-6 (1-912764-13-X) | 2019 | Isabel Vaz de Freitas · Jorge Marques |
| Portuguese: An Essential Grammar | 978-1-138-23434-5 (1-138-23434-6) | 2018 | Amelia P. Hutchinson · Janet Lloyd |