Table 1. Boolean equations.
| No. | Boolean equation |
|---|---|
| 1 | (“Science“ OR ”Natural Science“ OR ”Environmental education”) AND “democratic values” |
| 2 | (“Natural Science“ OR ”Environmental education”) AND “democratic values” |
| 3 | (“Natural Science“ OR ”Environmental education”) AND “learning” AND “democratic values” |
| 4 | (“STEM“ OR ”STEAM”) AND (“curriculum“ OR ”curricula“ OR ”education“ OR ”learning”) AND “democratic values” |
| 5 | (“Science“ OR ” Natural science“ OR ”Environmental education”) AND (“curriculum“ OR ”curricula“ OR ”learning”) AND “democratic values” |