Universal (Hexa)Decimal Classification

Since I have started with research over elliptic curves, many papers, book and other similar stuff has been read by me to take the knowledge. But there is an issue when the number of this things get too big. How can I organize the information of those papers (or books and so) in order to get back to this information and refresh the memory contents?

Very long a go, I did a course on bibliographic search and catalogue. In this course I have learned the way that the libraries in general organizes the books in there: the UDC (Universal Decimal Classification). I've looking how can I reuse this to classify the documents I think relevant for my research.

I have set up my own main classes and also I have tried to let at least one of them vacant for further updates, that mean to extend the fields of research. Event that pretension, by today, it's full again. This means that probably I'll have to do my second refactoring of this structure, because in the past I had once already this problem.

There is another way to modify my classification to have more vacants, that is think in another base. As far as I understood, the UDC was restricted from 0 to 9 to have like only one character field. Then why not a computer scientist can think in a Universal Hexadecimal Classification (UHC)?

For the records, my current main classes and their categories:

• 0.Mathematics
• 010.Number Theory
• 020.Abstract Algebra
• 030.Information Theory
• 040.Logic
• 050.Elliptic curves
• 1.Public Key
• 101.Finite fields cryptography
• 102.Elliptic curves cryptography
• 103.Hyperelliptic curves cryptography
• 110.Cryptoanalysis
• 111.Finite fields cryptoanalysis
• 112.Elliptic curves cryptoanalysis
• 113.Hyperelliptic curves cryptoanalysis
• 120.Isogenies
• 121.Isogeny volcanoes and stars
• 122.Isogenies cryptography
• 2.Symmetric cryptology
• 210.Rijndael
• 3.Hash functions
• 310.SHA
• 320.Elliptic and hyperelliptic curves
• 4.Stream cyphers
• 5.Secret sharing
• 6.Homomorphic encryption
• 7. vacant
• 8. vacant
• 9. vacant
• A. vacant
• B. vacant
• C. vacant
• D.Computation
• D10. Distributed systems
• D20. Parallel computing
• E.Hardware
• E10.Embedded systems
• E20.Smartcards
• E30.Rfid
• F.Standards
• F01.Internationals
• F10.European
• F20.North American
• F30.Russian

Because to the uncategorised classes, I think this is full and it's the first place to start merging classes and dividing them in categories. The solution of the hexadecimal, even if I have already applied, is not fixed for ever. May some day, certain categories would be subcategories. Currently this classification contains 409 documents (papers, books, and so on). My bibtex files aren't and they should.

What this system is not complaining is how to archive the notes that I wrote in the margins on the papers I read and place in here or the marks I set labelling pages on books, and so on. But this is an issue that this tool is not useful for.

How to have a search tool on this structure and inside those documents, including the posted comments?