I am looking for articles or books that would clearly and succinctly state the open problem of and issues with computing hadron masses and spins in QCD from first principles, preferably in relation to the open problem of confinement and the general open problem of non-perturbative QCD. Any suggestions? To clarify, I am not concerned with the truth of these issues, my question is a biblioraphical one: For purposes of citation I am hoping for an author who would state these problems clearly, comprehensively and authoratively. To compare, the Clay Institute announcement a few years back of the "Mass Gap Problem" serves as a great general purpose citation for the statement of the corresponding open problem in mathematical physics. What I am looking for is a similarly nicely citable statement of the corresponding problem in phenomenology. Some reference should say: Since non-perturbative QCD remains open, it is an open problem to derive the very existence of hadrons in the first place, and in particular to compute properties such as their masses and spin from first principles. Qualitative arguments and lattice simulations exist, but issues remain (e.g. proton spin crisis) and at the heart of it this is an open problem. Something like this. It seems people like to say all this in informal contexts, such as in popular physics journal columns, in Reddit replies or in their blog articles. None of which is citeable. I am looking for somebody saying all this clearly and in a regularly published article or book.