Greens function and the conducting sphere

[Gavroy]

Can somebody explain to me, when equations 2.48 and 2.50 are applicable and what $\Phi_s$ and $\Phi$ actually are? The thing is, I want to find a general equations that determines the field produced by conducting spherical sphere in an external field and was wondering whether these are the equations I am looking for.[Reference to 2.48 and 2.50][1]
http://physics.usask.ca/~hirose/p812/notes/Ch2.pdf

Or is it rather the equation here (17.3), probably they are one and the same:
[second reference][2]
http://www.physics.udel.edu/~jim/PHYS809_10F/Class_Notes/Class_17.pdf

 

[Valerie Park]

Equation 2.48 in the first reference is an expression for the electric potential of a point charge, and equation 2.50 is an expression for the electric potential of a spherical shell. The quantity $\Phi_s$ represents the potential at the surface of the shell, while $\Phi$ represents the potential at an arbitrary point within the shell. The equation in the second reference (17.3) is an expression for the electric field produced by a conducting spherical shell in an external field. This equation is more general than equations 2.48 and 2.50, as it takes into account the effects of the external field as well as the charges on the surface of the shell.