This is an interestingly ambiguous query! "3 one piece" could refer to a few different things. Here are the most likely interpretations, along with a notable paper (or concept) for each. You might be looking for an academic or analytical paper about a specific "Rule of Three" in One Piece (e.g., the Three Great Powers, the three types of Haki, the Monster Trio (Luffy, Zoro, Sanji), or the three ancient weapons).
This is an interestingly ambiguous query! "3 one piece" could refer to a few different things. Here are the most likely interpretations, along with a notable paper (or concept) for each. You might be looking for an academic or analytical paper about a specific "Rule of Three" in One Piece (e.g., the Three Great Powers, the three types of Haki, the Monster Trio (Luffy, Zoro, Sanji), or the three ancient weapons).