Could you point out some survey papers and monographs that highlight the kernel of tricks, techniques, and tools that Paul Erdős employed the most in his research work (in particular in graph theory, combinatorics, and number theory)?



Surveys of the items of Erdős' "toolbox"
Thank you @Fry, @so-calledfriendDon, and @DanPetersen (see comments) for these interesting references: 



> 
> Graham, Ronald L., Nešetřil, Jaroslav, Butler, Steve (eds.), *The
>  Mathematics of Paul Erdős* I and II, 2nd edition, Springer, 2013.
> 
> 
> Lovász, László, Ruzsa, Imre, Sós, Vera T. (eds.), *Erdös Centennial*,
>  Springer, 2013.
> 
> 
> Alon, Noga, Spencer, Joel H., *The probabilistic method*, 2nd edition,
>  Wiley-Interscience, 2000.
> 
> 
> 


