เล่มที่เกี่ยวข้องกับศิลปิน "Gorgoroth" จะออกเมื่อใด?
What are the issue dates of volumes associated with the artist "Gorgoroth"?
df_artist = pd.DataFrame(columns=['Artist_ID', 'Artist']); df_volume = pd.DataFrame(columns=['Issue_Date', 'Artist_ID'])
df_volume[df_volume['Artist_ID'].isin(df_artist[df_artist['Artist'] == 'Gorgoroth']['Artist_ID'])]['Issue_Date']