On 2015-09-09 at 19:42:25 +0100, Luke Kenneth Casson Leighton wrote:
"provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice; keep intact all notices stating that [...]
so that's in the source code.
also in non source: section 6 says
"You may convey a covered work in object code form under the terms of sections 4 and 5" (section 4 is the one quoted above)
similar wording is also in GPLv2