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.