1. Academic database: This is the main way to obtain mathematical papers. Commonly used academic databases include webofscience, Scopus, JSTOR, Springer Link, Elsevier Science Direct, etc. These databases contain a large number of mathematical journals and conference papers, which can be searched by keywords, authors, institutions and so on.

2. Google Academic: Google Academic is a free academic search engine, which can search a large number of mathematical papers. It includes not only the contents of the above-mentioned academic database, but also preprints, dissertations, patents and other types of documents.

3. Professional journals: Mathematical journals are also an important source of obtaining mathematical papers. Commonly used mathematical journals include Journal of Mathematics, Journal of Number Theory, Yearbook of Mathematics, Invention of Mathematics, etc. These periodicals generally have online editions, which can be directly searched on the periodical website.

4. Library: Libraries of universities and scientific research institutions usually subscribe to a large number of mathematical journals and conference papers, which is an important way to obtain mathematical papers. In addition, some libraries provide electronic resources, such as e-books and databases.

5. Academic social networks: such as ResearchGate and Academia.edu. Scholars on these platforms will share their research results, which can be downloaded or read directly.

6. Pre-printed servers: such as arXiv, bioRxiv, etc. These servers have a large number of mathematical preprints, which is an important way to obtain the latest research results.

7. Open access platform: PLOS, Biomedical Center, etc. The papers on these platforms are all open access, and you can read the full text directly.