A referendum in the Nov. 7 election in Troy will ask whether the City Charter should be amended to force city officials to gain voter approval of the sale, lease, transfer or use for more than 90 days of any public land parcel that is larger than 2 acres.The ballot question is the result of a residents' petition drive and is aimed at halting the city's plan to sell 127 acres at I-75 and Big Beaver Road, near City Hall, to a developer who will create a multi-use complex designed to make the area more walkable.