user: Question: who is the reference when romaji title is Heartbreak Sniper?
Columns: ['Romaji title', 'Japanese title', 'Release date', 'Reference', 'Oricon']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['TENCA wo Torou! ~Uchida no Yabou~', 'TENCAを取ろう~内田の野望', '1994/10/21', 'KIDS-220', 1.0]
SQL:

assistant: SELECT "Reference" FROM "Table" WHERE "Romaji title" = 'Heartbreak Sniper';