Hello Kuan Peng,
I highly recommend that you read two of Prof. Assis' books, which you
can find here:
https://www.ifi.unicamp.br/~assis/books.htm
"Ampère’s Electrodynamics – Analysis of the Meaning and Evolution of
Ampère’s Force between Current Elements, together with a Complete
Translation of His Masterpiece: Theory of Electrodynamic Phenomena,
Uniquely Deduced from Experience" – A. K. T. Assis and J. P. M. C. Chaib
(2015)
"Weber's Electrodynamics" – A. K. T. Assis (1994)
You will find them very enlightening.