Derek J.S. Robinson 
An Introduction to Abstract Algebra [PDF ebook] 

Frontmatter – Contents – Chapter 1. Sets, relations and functions – Chapter 2. The integers – Chapter 3. Introduction to groups – Chapter 4. Cosets, quotient groups and – homomorphisms – Chapter 5. Groups acting on sets – Chapter 6. Introduction to rings – Chapter 7. Division in rings – Chapter 8. Vector spaces – Chapter 9. The structure of groups – Chapter 10. Introduction to the theory of – fields – Chapter 11. Galois theory – Chapter 12. Further topics – Backmatter

Derek J. S. Robinson is Professor of Mathematics at the University of Illinois in Urbana-Champaign, USA.