1998 Question A of the National Mathematical Modeling Competition for College Students? Is the topic the return and risk of investment? If so, I know where to look. There is an article in my space that specifically links to the papers of 1992-2008 National Mathematical Modeling Competition for College Students. The address is in the resources.

You can also go to Baidu Saicai's mathematical modeling forum, where there are many papers on mathematical modeling that can be downloaded. It is said that there are mentors on it, and I often hang out on it. I think this forum is good. If you go to that forum, the articles from 1992 to 2008 should be top articles, or you can go to my space to see that link.