Utah Math Visions
ASSISTments has many problems from Utah Math Visions Project for high school (http://www.mathematicsvisionproject.org). The content is marked as being released under a Creative Common License.
All Creative Common's licenses requires that people that redistribute such content need to do 4 things. 1) give a attribution on who the authors are/where it came from, 2) republish a link the exact Creative Common license that it came from so others will know the license to cite, 3) provider a disclaimer that the original authors are not endorsing WPI's use(or our changes) and finally to 4) to state if we know if the material is copyrighted. We will now do these 4 steps.
First, for attribution this material comes from a group that called themselves the Math Vision Project. See mathematicsvisionproject.org. The authors are listed as Scott Hendrickson, Joleigh Honey, Barbara Kuehl, Travis Lemon & Janet Sutorius.
Second, the exact license. There is some discrepancy between pages at the cite. Some say CC-BY-4.0 while others claim CC-BY-NC-SA-4.0. WPI does not care which, as we are not using these for commercial purposes. For instance https://www.mathematicsvisionproject.org/secondary-mathematics-ii.html has a CC-BY-NC-SA symbol, but this page (https://www.mathematicsvisionproject.org/uploads/1/1/6/3/11636986/m2_mod1_se_22017f.pdf) says CC-BY-4.0 .
Third, that page also claims copyright, to quote, is "© 2017 Mathematics Vision Project Original work © 2013 in partnership with the Utah State Office of Education".
Last, we provide the disclaimer that the Math Vision Project in do way endorses our use. All errors on our website are WPI's fault. And to be clear, we are making small modifications to make sure the questions can be answers by computer. For instance, we have tried our best to put the same material into ASSISTments but errors happen. To give an example, we had a copy-paste error the other day reported where we copied the "1/2" symbol but it pasted as "12". We have corrected the errors when we have been informed about them. Also, we have made to modify the content to make it gradeable by computer. For instance we would sometime have to specify how many digits to round your answer to. But we have tried to stay as consistent with the author's intent.
We would like to thank the authors for releasing this free resource.