Williams, P. M. (February 1975), Stellar compositions from narrow-band photometry - V. Barium abundances for 200 evolved stars, Monthly Notices of the Royal Astronomical Society, 170 (2): 343–362, Bibcode:1975MNRAS.170..343W, doi:10.1093/mnras/170.2.343.
Williams, P. M. (February 1975), Stellar compositions from narrow-band photometry - V. Barium abundances for 200 evolved stars, Monthly Notices of the Royal Astronomical Society, 170 (2): 343–362, Bibcode:1975MNRAS.170..343W, doi:10.1093/mnras/170.2.343.