Which online databases/digital libraries are good for for programmers?
When I have a problem I often search the computing literature.


Some of the resources[*] I use are:

  - [ACM Digital Library][1]
  - [IEEE Xplore][2]
  - [Lecture Notes in Computer Science][3] 
  - [HCI Bibliography][4]

What do you use? What is the best resource source (if there is one) for the working programmer?

 [\*] after stackoverflow and google of course :) 

PS what tags should I use for this question?

  [1]: http://portal.acm.org/dl.cfm
  [2]: http://ieeexplore.ieee.org/Xplore/dynhome.jsp
  [3]: http://www.springerlink.com/content/105633/
  [4]: http://www.hcibib.org/
Which online databases/digital libraries are good for for programmers?
===

When I have a problem I often search the computing literature.


Some of the resources[*] I use are:

  - [ACM Digital Library][1]
  - [IEEE Xplore][2]
  - [Lecture Notes in Computer Science][3] 
  - [HCI Bibliography][4]

What do you use? What is the best resource source (if there is one) for the working programmer?

 [\*] after stackoverflow and google of course :) 

PS what tags should I use for this question?

  [1]: http://portal.acm.org/dl.cfm
  [2]: http://ieeexplore.ieee.org/Xplore/dynhome.jsp
  [3]: http://www.springerlink.com/content/105633/
  [4]: http://www.hcibib.org/