As I’ve previously written, I think textbook publishers Holt, Rinehart and Winston clearly provide the best online multilingual resources of all the major publishers. Earlier in August, though, they inexplicably took much of them off-line.
After some frustrating attempts at communicating with them online, this afternoon I gave them a call. After spending an hour on the phone with them, they discovered that it was a technical glitch. The resources are now back online and available!
You can read the specifics about how to access them at The Best Multilingual & Bilingual Sites For Math, Social Studies, & Science.
Many thanks to Holt!