I have read chapters 1 to 4 and so far found this book explained clearly for an undergraduate assuming you have knowledge of special relativity and electrodynamics and modern physics.<br><br>I am a retired electrical engineer and had only studied classical physics (Newtonian &amp; Maxwellian) 40 years ago during my university days "Down Under". But no worries, if you do not understand chapters 2,3 &amp; 4, the following books are very helpful as I had referred to them to help me understand the required chapters 2,3 &amp; 4:<br><br>(A) Relativity(4 vectors) and Electrodynamics<br>(1) Introduction to Electrodynamics by David Griffiths<br>Chapter 10 Potentials and Fields<br>Chapter 12 Relativity and Electrodynamics<br>(2) Introduction to Elementary Particles by David Griffiths<br>Chapter 3 Relativistic Kinematics<br><br>If you have not come across the Dirac Notation, the following books help:<br>(B) Quantum Mechanics<br>(1) Quantum Physics for Dummies by Steven Holzner<br>(2) Quantum Mechanics Demystified by David McMahon<br>(3) Quantum Mechanics by David McIntyre<br>(4) A Modern Approach to Quantum Mechanics by John Townsend<br><br>If you have problems with matrices, the following books are helpful:<br>(C) Linear Algebra<br>(1) A First Course in Linear Algebra by Moore &amp; Yaqub<br>(2) A Modern Introduction to Linear Algebra by Henry Ricardo<br><br>(D) Modern Physics<br>(1) Modern Physics by Randy Harris<br>(2) Concepts of Modern Physics by Arthur Beiser<br><br>If you need a brief chapter on Lagrangian and Hamiltonian, this book helps:<br>(E) Classical Mechanics<br>(1) Classical Mechanics - A Modern Perspective by Barger &amp; Olsson<br><br>Hope the above is useful to undergraduates as I was once like you 40 years ago "Down Under" trying to understand the lecturer's explanation.<br><br>Regards, Philip,Sarawak,Borneo,East Malaysia.