Update README.md

README.md

@@ -14,11 +14,11 @@ CoCo-trie compresses and collapses subtrees in a principled and effective  way.
 
 It hinges upon a data-aware optimisation scheme that selects the best subtries to collapse based on a pool of succinct encoding schemes in order to minimise the overall space occupancy.
 
-An introduction to the string dictionary problem, a motivating example, a detailed description of CoCo-trie with proof about the space and time complexity, and experiments against well-established and highly-engineered trie-based string dictionaries are in the paper: [(DOI)](https://doi.org/10.1016/j.is.2023.102316) [(PDF)](https://pages.di.unipi.it/boffa/files/IS.pdf)
+An introduction to the string dictionary problem, a motivating example, a detailed description of CoCo-trie with proof about the space and time complexity, and experiments against well-established and highly-engineered trie-based string dictionaries are in the paper: [(DOI)](https://doi.org/10.1016/j.is.2023.102316) [(PDF)](https://www.boffa.top/files/IS.pdf)
 
 >  Antonio Boffa, Paolo Ferragina, Francesco Tosoni, and Giorgio Vinciguerra. CoCo-trie: Data-aware compression and indexing of strings.  In: Information Systems 120 (2024), p. 102316 [https://doi.org/10.1016/j.is.2023.102316](https://doi.org/10.1016/j.is.2023.102316)
 
-Preliminary results appeared in the paper: [(DOI)](https://doi.org/10.1007/978-3-031-20643-6_17) [(PDF)](https://pages.di.unipi.it/boffa/files/SPIRE.pdf)
+Preliminary results appeared in the paper: [(DOI)](https://doi.org/10.1007/978-3-031-20643-6_17) [(PDF)](https://www.boffa.top/files/SPIRE.pdf)
 
 >  Boffa, A., Ferragina, P., Tosoni, F., Vinciguerra, G. (2022). Compressed String Dictionaries via Data-Aware Subtrie Compaction. In: Arroyuelo, D., Poblete, B. (eds) String Processing and Information Retrieval. SPIRE 2022. Lecture Notes in Computer Science, vol 13617. Springer, Cham. [https://doi.org/10.1007/978-3-031-20643-6_17](https://doi.org/10.1007/978-3-031-20643-6_17)