diff --git a/books/free-programming-books-subjects.md b/books/free-programming-books-subjects.md
index a1e4ae517..9ae5f92bf 100644
--- a/books/free-programming-books-subjects.md
+++ b/books/free-programming-books-subjects.md
@@ -90,9 +90,9 @@ Books that cover a specific programming language can be found in the [BY PROGRAM
 
 ### Algorithms & Data Structures
 
-* [A Field Guide To Genetic Programming](https://web.archive.org/web/20191020195105/http://www0.cs.ucl.ac.uk/staff/W.Langdon/ftp/papers/poli08_fieldguide.pdf) - Riccardo Poli, William B. Langdon, Nicholas F. McPhee (PDF) *(:card_file_box: archived)*
+* [A Field Guide To Genetic Programming](https://web.archive.org/web/20191020195105/http://www0.cs.ucl.ac.uk/staff/W.Langdon/ftp/papers/poli08_fieldguide.pdf) - Riccardo Poli, William B. Langdon, Nicholas F. McPhee (PDF) *(:card_file_box: archived)* (CC BY-NC-ND)
 * [Algorithm Design](https://archive.org/details/AlgorithmDesign1stEditionByJonKleinbergAndEvaTardos2005PDF) - Jon Kleinberg, Éva Tardos
-* [Algorithmic Graph Theory](https://code.google.com/p/graphbook/) - David Joyner, Minh Van Nguyen, David Phillips (PDF)
+* [Algorithmic Graph Theory](https://code.google.com/p/graphbook/) - David Joyner, Minh Van Nguyen, David Phillips (PDF) (GFDL)
 * [Algorithmic Thinking](https://labuladong.gitbook.io/algo-en) - Donglai Fu
 * [Algorithms](https://en.wikibooks.org/wiki/Algorithms) - Wikibooks
 * [Algorithms](https://jeffe.cs.illinois.edu/teaching/algorithms/book/Algorithms-JeffE.pdf) - Jeff Erickson (PDF)
@@ -254,7 +254,7 @@ Books that cover a specific programming language can be found in the [BY PROGRAM
 * [CI/CD for Monorepos: Effectively building, testing, and deploying code with monorepos](https://github.com/semaphoreci/book-monorepo-cicd) - Pablo Tomas Fernandez Zavalia, Marko Anastasov, SemaphoreCI (PDF, EPUB, Kindle)
 * [CI/CD with Docker and Kubernetes Book](https://github.com/semaphoreci/book-cicd-docker-kubernetes) - Marko Anastasov, Jérôme Petazzoni, Pablo Tom F. Zavalia, SemaphoreCI (PDF, EPUB, Kindle)
 * [Docker Jumpstart](https://odewahn.github.io/docker-jumpstart/) - Andrew Odewahn
-* [Docker Tutorial](https://people.irisa.fr/Anthony.Baire/docker-tutorial.pdf) - Anthony Baire (PDF)
+* [Docker Tutorial](https://people.irisa.fr/Anthony.Baire/docker-tutorial.pdf) - Anthony Baire (PDF) (CC BY-NC-ND)
 * [Docker Tutorial](https://www.tutorialspoint.com/docker/) - Tutorials Point (HTML, PDF)
 * [Dotnet Microservices Architecture for Containerized NET Applications](https://aka.ms/microservicesebook) - Cesar de la Torre, Bill Wagner, Mike Rousos (PDF)
 * [Kubernetes Deployment & Security Patterns](https://resources.linuxfoundation.org/LF+Projects/CNCF/TheNewStack_Book2_KubernetesDeploymentAndSecurityPatterns.pdf) - Alex Williams (PDF)