Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page United Kingdom of the Netherlands:

"

William I refused to accept the secession of Belgium. In August 1831, he launched the Ten Days' Campaign, a major military offensive into Belgium. Though initially successful, the French intervened to support the Belgians and the invasion had to be abandoned.[1] After a period of tension, a settlement was agreed at the Treaty of London in 1839. The Dutch recognised Belgian independence, in exchange for territorial concessions.[2] The frontier between the two countries was finally fixed by the Treaty of Maastricht in 1843. Luxembourg became an autonomous state in personal union with the Dutch, though ceding some territory to Belgium.[citation needed]