I don't know about the other networks, but for Facebook, you can simply locate the Page using a combination of API Search:
https://graph.facebook.com/search?q=New%20York%20Times&type=page
This will return a lot of Page IDs:
{
"data": [
{
"name": "The New York Times",
"category": "Media/news/publishing",
"id": "5281959998"
},
{
"name": "W New York - Times Square",
"category": "Hotel",
"id": "107574351937"
},
{
"name": "The New York Times Crossword Puzzle",
"category": "Community",
"id": "230891537029840"
},
{
"name": "The New York Times Travel Show",
"category": "Company",
"id": "135183981456"
},
{
"name": "InterContinental New York Times Square",
"category": "Travel/leisure",
"id": "225795063575"
},
{
"name": "Well | The New York Times",
"category": "Media/news/publishing",
"id": "181548405298864"
},
...
}
For most major companies, you can probably assume that the first ID in the list is the correct page. You could check by looking up each ID like so:
https://graph.facebook.com/5281959998
You will see in response two fields that are relevant: website
and likes
Likes will show the number of fans that the page have (you can probably assume that the one with the most fans is the correct page) and website will provide the company-specified URL of their website.