In Scotland, Scots is spoken in the Scottish Lowlands, the Northern Isles, Caithness, Arran and Campbeltown. In Ulster, the northern province in Ireland, its area is usually defined through the works of Robert John Gregg to include the counties of Down, Antrim, Londonderry and Donegal (especially in East Donegal and Inishowen). More recently, the Fintona-born linguist Warren Maguire has argued that some of the criteria that Gregg used as distinctive of Ulster Scots are common in south-west Tyrone and were found in other sites across Northern Ireland investigated by the Linguistic Survey of Scotland. Dialects of Scots include Insular Scots, Northern Scots, Central Scots, Southern Scots and Ulster Scots.