NGC 6881 - WHT 4,2m - Ramos-Larios, Guerrero, Miranda - (H2)
NGC 6881 - Hubble Space Telescope - Kwok, Borkowski, Balik
NGC 6881 - IAC - Manchado, Guerrero, Stanghellini - (R;G;B = [NII]; Halpha; [OIII])