| SI.N | Code book used (Description) | IS Code number |
|---|---|---|
| 1319 | Handbook on Water Supply and Drainage (with Special Emphasis on Plumbing) | SP 35:1987 |
| SI.N | Code book used (Description) | IS Code number |
|---|---|---|
| 1319 | Handbook on Water Supply and Drainage (with Special Emphasis on Plumbing) | SP 35:1987 |