Dimensional analysis with wingspan length? I need some help in understanding the fundamentals of dimensional analysis. 
The following is is from "Fundamentals of aerodynamics" by John D Anderson, fifth edition:
 

Why is the wingspan length not added to the variables that the aerodynamics force R depend on?
In page 38 of the book you're quoting, the derivation goes on replacing $c^2$ with $S$,   the planform area of the wing, implicitly introducing the wingspan...