Frankfurt School Texts
I have recently added about 10 texts from various philosophers from the Frankfurt School. Some of these texts are now almost a century old, but they are still relevant. It's interesting to look back at their analysis: The had deep insight, but they could not really anticipate what would happen to humanity at the beginning of the 21st century.
Here is a link to the texts.
Here's some good reference for literature, religion, philosophy, quotations, Mythology, etc.