I'm just going to help you out on something I see far too often with people on the internet. There's a way to find sources yourself. It's called Google. Now here you have a list of supposed terror drills. Now all you would need to do is, instead of replying "That "list" has no sources" like some english teacher in school would say, go to http://www.google.com. Once the page loads up type this into the search field (we'll start with the first one on the list):

9/11 terror drills

And then simply press the enter key on your keyboard or click the search icon to the right of the search field.

Now google will bring up page which match the search. Now here's the fun part. Which source is a good source? Well here's where you have to use your own common sense and find one that is credible to you. Is Wikipedia credible? I say it is for this purpose so click on the wikipedia link. It's the 2nd link for me and might be different for you.

Now go to the wikipedia page and read all about the "terror drills" on 9/11. And if you want, go back to the list and read more info on it from more sources and then make up your mind about whatever this means, if it means anything at all.

Next search:

london subway terror drills

The same way you searched before. And look down through the list again and we see wikipedia again. So let's click on that. Do this for the whole list. You don't have to just click on wikipedia links. You can find links from sources like CNN/MSNBC/CBS/ABC, whatever floats your boat.

Anyways I hope you enjoyed this little tutorial on researching sources yourself without the help of others! Good day to you fine sir or madam. And don't forget to brush your teeth!