diff --git a/free-programming-books.md b/free-programming-books.md
index d919ce9b5f379afa5f2d36745b7d7a03cb794e1b..8f18534f4210fccb82d5c249f23a3a5ae2a05e89 100644
--- a/free-programming-books.md
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@@ -329,11 +329,14 @@
 #### Database
 
 * [Big Data Now: Current Perspectives from O'Reilly Radar](http://shop.oreilly.com/product/0636920022640.do)
+* [Database Explorations](http://www.dcs.warwick.ac.uk/~hugh/TTM/Database-Explorations-revision-2.pdf)
 * [Database Fundamentals](http://public.dhe.ibm.com/software/dw/db2/express-c/wiki/Database_fundamentals.pdf) (PDF)
+* [Databases, Types, and The Relational Model: The Third Manifesto](http://www.dcs.warwick.ac.uk/~hugh/TTM/DTATRM.pdf)
 * [Foundations of Databases](http://webdam.inria.fr/Alice/)
 * [Readings in Database Systems, 5th Ed.](http://www.redbook.io)
 * [Temporal Database Management](http://people.cs.aau.dk/~csj/Thesis/) - Christian S. Jensen
 * [The Theory of Relational Databases](http://web.cecs.pdx.edu/~maier/TheoryBook/TRD.html)
+* [What is Database Design, Anyway?](http://www.oreilly.com/data/free/what-is-database-design-anyway.csp)
 
 
 #### Datamining