Today marks the 15th anniversary of what my research has uncovered was the closest vote in the history of independence referendums: 49.4% voting in favour of a sovereign Quebec, 50.6% voting against. The tabulation of the vote is preserved here on the website of Quebec's Director General of Elections, broken out riding by riding (ie., district by district): http://dgeq.qc.ca/francais/tableaux/referendum-1995-8481.php
As can be seen, the "Yes" campaign won most of the districts, but by relatively small majorities, with their biggest majority coming in Saguenay, with 73.3% voting in favour. The "No" supporters were much more concentrated in a small number of districts, including Westmount where 84.8% voted against, Saint-Laurent 82.8%, Robert-Bawldwin 89.8%, D'Arcy-McGee with a remarkable 96.4% No. These areas are all in the western neighbourhoods of Montreal, which have a large English-speaking population. Polls showed that less than 10% of Quebecers with a first language other than French voted in favour; where that first language was English, it was much lower still. Also delivering a high "No" vote was Pontiac, with 87.2% against. It also has a large English-speaking population. It is also near Ottawa and has a large number of people who work for Canada's federal government, who of course would have little to gain from an independent Quebec.