Literary Criticism for Two Short Stories?

[Carla]

I am currently taking an English 102 course and am reading The Cask of Amontillado by Edgar Allan Poe and My Last Duchess by Robert Browning. I am suppose to find 5 online sources of literary criticism for each story (Total of 10). Problem is finding them. My teacher does not want any use of websites like helium or anything like that. She wants us to use reliable sources, coming from sites like .edu, .org, or .net. If anyone can give me a guide to where I can find these it would be greatly appreciated! Sidenote..... I am not writing anything based off of these papers, we are simply using them as guides to show the different views and comparisons of both these stories.