| 1 | Overview of primary and secondary education programs from 1923 to the present | 4,5,6 |
| 2 | Qualitative analysis and document review in outline | 1,2 |
| 3 | MaxQDA qualitative analysis program | 3 |
| 4 | Theoretical frameworks that help the analysis of textbooks | |
| 5 | Science education between 1923-1932 | 7,8,18 |
| 6 | Science education between 1932-1948 | 8,18 |
| 7 | Science education between 1948-1968 | 9,10,18 |
| 8 | Science education between 1968-1992 -I | 11,12,18 |
| 9 | Science education between 1968-1992 -II | 11,12,18 |
| 10 | Science education between 1992-2000 | 13,18 |
| 11 | Science education between 2000-2005 | 14,18 |
| 12 | Science education between 2005-2013 | 15,18 |
| 13 | Science education between 2013-2018 | 16,18 |
| 14 | Science education from 2018 to present | 17,18 |