PaperDb is one of the largest paper databases available and for most users it's completely free to use. We have provided documentation for the API that we provide and if you need specific functions not already available, we are happy to look into this. On this website you can see examples of code as well as samples from the actual database. You can also read about terms and why we offer this as a free service.
Feel free to reach out if you have any queries or wish to work together.
Morten B. Reitoft