I just add a supplementary, I think Mr. hirnyk's answer is appropriate, the information of mapleprimes is too large. And Mr. Christopher2222 's method is very convenient. The following is another one to save some helpful pages as pdf format.
Some pages are helpful and want to download and save them, one way is:1, install adobe acrobat software, which is used to read pdf format files, and can be easily found in google to download. 2, click the "file" menu of the browser, and chose "print...", then a dialog box appeared, and chose the virtual printer named "Adobe PDF", finally, click print button in the bottom, then a pdf file will be generated and can be saved in your computer.
The appendant is a pdf file generated by this method.1.pdf