In the Treaty of Westphalia, wikipedia states it was agreed states would control their agents? Are there any non wikipedia sources for this?

by hotdogofchina

the exact relevant text

'General recognition of the exclusive sovereignty of each party over its lands, people, and agents abroad, and responsibility for the warlike acts of any of its citizens or agents. Issuance of unrestricted letters of marque and reprisal to privateers was forbidden.'

I am looking for help finding an academic source I could use for this information! Thanks

morg-thor