| GRPE-79-24 | Status report of the EPPR informal working group | |
| GRPE/2019/12 | GTR 2: Proposal for Amendment 4 | |
| GRPE-79-21/Rev.1 | GTR 2: Consolidated text incorporating Amendment 4 | |
| GRPE/2019/12 | GTR 2: Proposal for Amendment 4 | |
| GRPE-79-22 | GTR 2: Technical report on the development of Amendment 4 |