In MEW we do our best to run series concurrently, there is an index published every twelve issues and the next issue will have the index for issues 201 to 212 in it.
All three of the articles you mention have been published 'end to end'.
Traditionally ME published articles every other issue for many years. David Clark phased this out, but Diane is reintroducing it. The argument is that it allows greater variety of content in a fortnightly magazine (and lets long series writers have a chance to keep up!)
There are various indexes for each magazine available on line or on CD, with different pros and cons, that you might use. Also, if you get really stuck either ask on here or if you get really stuck email me at neil.wyatt@mytimedia.com (within reason!)
Neil