in this link there is a short text about Artin's primitive roots conjecture.in part 4:
where $\sum\limits_{nsquarefree} {\frac{{\mu \left( n \right)}}{{\left[ {{K_n}:Q} \right]}}}$ come from?
what is $Q\left( {{\zeta _q},{a^{\frac{1}{q}}}} \right) $?
if there is some one that want to help me more please leave a comment then I give you my email address.thanks a lot