With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Zinedine Zidane headbutted Marco Materazzi in the chest.
text_B: Come Blow Your Horn is an album recorded by Canadian jazz trumpeter Maynard Ferguson in 1963 which was originally released on the Cameo label .. Maynard Ferguson. Maynard Ferguson. Cameo. Cameo-Parkway Records
not_related.