The spectra of weighted shifts Since weighted shifts are like the model-operators in operator theory and people have been studying them for so long, I think there should be quite a large literature on the spectra of such operators. However, after some search I hardly found anyone which gives a complete picture of what the spectra of a weighted shift.
Most of the papers I found deal with some specific properties of their spectra, but the question I have in mind is what the spectra are, exactly.
I wonder whether there is some good reference on this.
Thanks!

For complete description of the spectra of weighted shifts, see either
1: A.L. Shields, Weighted Shift Operators and Analytic Function Theory, in Topics in Operator Theory, Mathematical Surveys, N0 13 (ed. C. Pearcy), pp. 49-128. American Mathematical Society, Providence, Rhode Island 1974
Or
2: http://surface.syr.edu/cgi/viewcontent.cgi?article=1138&context=mat 
Or
3: https://www.impan.pl/shop/publication/transaction/download/product/90721
