at five weeks later vs five week later

Some examples from the web:

• The molten steel was found 'three, four and five weeks later.
• Five weeks later, I was back in the car in monza.
• Five weeks later, I was down 240 feet... trying to get a line around the Squalus when he died.
• Five weeks later he was in Vienna tearing up English newspapers, rearranging the items and pretending he was Tulse Luper.
• Five weeks later the German army had smashed its way to within 18 miles of Paris.
• Five weeks later, I was down 240 feet trying to get a line around the Squalus when he died.
• And when I leave town five weeks later, you get the benefit.
• The molten steel was found 'three, four and five weeks later, when the rubble was being removed'.
• The first injection should be given in cats aged at least eight weeks, with a second injection three to five weeks later.
• The molten steel was found "three, four, and five weeks later, when the rubble was being removed."
• Five weeks later we debated the reports by Mr Karas on the two regulations here in the plenary of the European Parliament, which is another demonstration of the good spirit of cooperation in which this Parliament has dealt with this important issue.
• Beforehand, they simply explained five or six weeks later, when they published the minutes of their deliberations.
• Last of the P.O.W.'s got back from the Philippines and a week later five kids died.
• The first treatment is then consolidated, three to four weeks later, by giving TRISENOX once daily for five days, followed by a two-day break, repeated for five weeks.
• He should've caught this, even at five weeks.
• A week later, he shows up with five bullets in him because someone shot him in cold blood.
• Securities issues statistics are transmitted to the ECB no later than five weeks after the end of the months to which the data relate.
• Securities issues statistics shall be transmitted to the ECB no later than five weeks after the end of the months to which the data relate.
• All draft opinions and other discussion documents requiring translation shall be sent to the secretariat of the commission in question not later than five weeks before the date set for the meeting.
• The first eruption happened here, five weeks ago off the coast of Spain, then here, two days later at Aratonga in the South Pacific.

Some examples from the web:

• The molten steel was found 'three, four and five weeks later.
• Five weeks later, I was back in the car in monza.
• Five weeks later, I was down 240 feet... trying to get a line around the Squalus when he died.
• Five weeks later he was in Vienna tearing up English newspapers, rearranging the items and pretending he was Tulse Luper.
• Five weeks later the German army had smashed its way to within 18 miles of Paris.
• Five weeks later, I was down 240 feet trying to get a line around the Squalus when he died.
• And when I leave town five weeks later, you get the benefit.
• The molten steel was found 'three, four and five weeks later, when the rubble was being removed'.
• The first injection should be given in cats aged at least eight weeks, with a second injection three to five weeks later.
• The molten steel was found "three, four, and five weeks later, when the rubble was being removed."
• Five weeks later we debated the reports by Mr Karas on the two regulations here in the plenary of the European Parliament, which is another demonstration of the good spirit of cooperation in which this Parliament has dealt with this important issue.
• Beforehand, they simply explained five or six weeks later, when they published the minutes of their deliberations.
• Last of the P.O.W.'s got back from the Philippines and a week later five kids died.
• The first treatment is then consolidated, three to four weeks later, by giving TRISENOX once daily for five days, followed by a two-day break, repeated for five weeks.
• A week later, he shows up with five bullets in him because someone shot him in cold blood.
• Securities issues statistics are transmitted to the ECB no later than five weeks after the end of the months to which the data relate.
• Securities issues statistics shall be transmitted to the ECB no later than five weeks after the end of the months to which the data relate.
• All draft opinions and other discussion documents requiring translation shall be sent to the secretariat of the commission in question not later than five weeks before the date set for the meeting.
• The first eruption happened here, five weeks ago off the coast of Spain, then here, two days later at Aratonga in the South Pacific.
• And then, about a week later, I get a knock on my door from some surf shop saying that the board is actually theirs, and I owe them five days rental.