Measurements of $$\pi ^\pm $$, $$K^\pm $$, p and $$\bar{p}$$ spectra in $$^7$$Be+$$^9$$Be collisions at beam momenta from 19A to 150A $${\mathrm{Ge} \mathrm{V}}\!/\!c$$ with the NA61/SHINE spectrometer at the CERN SPS
European physical journal. C, Particles and fields