Summary
- adding slugs for articles 15, 20, 21, 22. Currently missing reference lists. (commit: 0d24131) (details)
| The file was added | content/Articles/S000015.md | 
| The file was added | content/Articles/S000022.md | 
| The file was added | content/Articles/S000021.md | 
| The file was added | content/Articles/S000020.md | 
