General Heywood Kirk, who may have been an ancestor of Captain James T. Kirk, looked through the research into UFOs from the mid-1960s and cited magazine articles that dealt with the topic in the 'Time Tunnel' episode "Visitors From Beyond The Stars".
These turned out to be real magazine articles that can be found here in the real world.
1] Look Magazine (October 1966) - about a couple who had been brought on board a UFO.
This would be Barney and Betty Hill. Their story was even dramatized and made part of the TV Universe in "The UFO Incident" aka "Interrupted Journey".
2] Life Magazine (4/1/1966) - reports of sightings near Perth, Australia.
The cover of that issue of Life is reproduced here. As you can see, one of the cover stories is about the week of flying saucers
3] General Kirk also mentioned 60 people around Kensington, New Hampshire, who saw a UFO in September, 1965. The event led to the publication of a book called "Incident At Exeter".