| Number of publications (%) | Study nacionality |
| 17 (64.4%) | Brazil |
| 1 (3.8%) | Spain |
| 1 (3.8%) | Portugal |
| 1 (3.8%) | Singapore |
| 1 (3.8%) | Pakistan |
| 1 (3.8%) | China |
| 1 (3.8%) | Israel |
| 1 (3.8%) | Italy |
| 1 (3.8%) | Thailand |
| 1 (3.8%) | Philippines, Greece and Nigeria |