Thread:ADour/@comment-5679696-20161130030343/@comment-4651179-20161130040134

The best answer I can think of involves being at least slightly familiar with the character or the story. If you read an unreferenced paragraph and recognize where its information could have come from, with some re-reading you can probably find the source.

For example, looking at the section you mentioned, I'm not very familiar with Wiccan pre-Young Avengers Volume 2, but I do remember an issue of New Avengers where Doctor Strange talked with him and they were attacked by the Hood. I googled "Wiccan Doctor Strange New Avengers Dark Reign" and New Avengers #51 came up. I went to my comic collection, took a look at it, and found it's indeed where Strange's reunion with Billy happened (with Hood's attack having happened in #52)

It's also useful if the unreferenced paragraph belongs to some section with a header. It helps narrow the search. If the unreferenced information is present in the section titled "Dark Reign and The Siege," you know you would have to look for an answer in comics from that period specifically.