Sources for UFO sighting quotes made by US Astronauts

I've been surfing this topic for the past couple hours and I decided to just post it here since so many ATS members have great references and website links. I'm looking for the sources (names of newspapers, magazines, whatever) for the quotes of certain US astronauts who have seen UFO's.

I google search "UFO Sightings by US Astronauts" and I get a huge list of websites, but when I look at each website they contain almost the exact quotes but no one lists sources for the statements allegedly being made by US astronauts.

I'll give two examples:

Donald Slayton a Mercury astronaut revealed in an interview he had seen UFOs in 1951:

"I was testing a P-51 fighter in Minneapolis when I spotted this object. I was at about 10,000 feet on a nice, bright, sunny afternoon. I thought the object was a kite, then I realized that no kite is gonna fly that high."

As I got closer it looked like a weather balloon, gray and about three feet in diameter. But as soon as I got behind the darn thing it didn't look like a balloon anymore. It looked like a saucer, a disk.

About the same time, I realized that it was suddenly going away from me -- and there I was, running at about 300 miles per hour. I tracked it for a little way, and then all of a sudden the damn thing just took off. It pulled about a 45 degree climbing turn and accelerated and just flat disappeared."

AND

NASA's Scott Carpenter

"At no time, when the astronauts were in space were they alone: there was a constant surveillance by UFOs."

These are only two examples and there are many more. These are great quotes about UFOs but WHO conducted these interview or WHERE did these quotes appear in print? The websites post only the quotes and never the source info. It is not that I do not believe these US Astronauts did not make these claims. It is just that I do not trust random quotes on website that do not list a source. I want to write up an article on this subject but I cannot do that without valid sources. Can anyone help me find the sources for these quotes?

Its always amazing what the astronauts see and what they choose not to say. There are also Youtube videos of a conference in which the astronauts talk of some of these sights.

youtube.com...
First one.
youtube.com...
Second one.

Pretty sure there are more, but I figured I'd just throw these two clips in to help spread the point that these websites aren't merely writing whatever they want, but that these astronauts are actually seeing things in space that they can't explain at the time. Perhaps its something or perhaps space junk, that all depends on one's own opinion.