Who sell "No Parking" signs?

If you cannot find any, you can just write it in a piece of paper with big fonts and laminate it.

My dear friend its quite easy , its availiable in al safety items selling shop if you are in doha, ther are some shops near to the sword signal ,

or else you can straight head to Industrial area, street 30 in front of bolts and tools shop there is a safety items shop.. and a lot more on the same street,

thanks

raj