english: Building on Galaxy Zoo, the researchers completed Galaxy Zoo 2 which collected more than 60 million more complex morphological classifications from volunteers (Masters et al. 2011).
non_english: Bangunan ing Zoo Galaxy, peneliti rampung Galaxy Zoo 2 kang diklumpukake luwih saka 60 yuta liyane klasifikasi morfologi Komplek saka sukarelawan (Masters et al. 2011) .