a couple of hour vs a couple of hours

Some examples from the web:

• Only started a couple of hour ago.
• Although you wouldn抺 be able to touch or smell these models, it will surely keep you busy or in wonderland for a couple of hour at least.
• In the afternoon we enjoy a couple of hour of relaxation in the swimming pool of the hotel before immerse ourselves in the nightlife of Kusadasi till late in the night!
• Curtis peck was found murdered a couple of hours ago.
• Please try downloading again after a couple of hours.
• I called for these reservations a couple of hours after our Art History midterm.
• I have to make a telephone call to California in a couple of hours.
• It's been doing that for a couple of hours.
• I was only gone a couple of hours.
• For a couple of hours anyway.
• We still have a couple of hours.
• The programs start in a couple of hours.
• No flights in or out of logan for a couple of hours.
• I'd say a couple of hours before. Ryan, track down the delivery guy.
• And Summit's only a couple of hours from where the body was found.
• I could be there in a couple of hours.
• I'd say a couple of hours before.
• Then we have a couple of hours.
• I rested for a couple of hours, and then...
• It's a couple of hours.

Some examples from the web:

• Please try downloading again after a couple of hours.
• I called for these reservations a couple of hours after our Art History midterm.
• Special Agent Kerry SouthWeIl, she died a couple of hours ago.
• We got word a couple of hours ago.
• We located it a couple of hours ago.
• Morrie Friedman called a couple of hours ago.
• We still have a couple of hours.
• No flights in or out of logan for a couple of hours.
• I'd say a couple of hours before.
• Then we have a couple of hours.
• I rested for a couple of hours, and then...
• It's a couple of hours.
• We could still spend a couple of hours there.
• Nutsy, you'd better set your brains ahead a couple of hours.
• Just a couple of hours or so.
• In a couple of hours would be better.
• Train's not for a couple of hours.
• Surgery's only a couple of hours.
• You can take her home in a couple of hours.
• Frank needs to borrow a suit for a couple of hours.