To ensure you're downloading from a legitimate source:
What I can do instead is provide a of the topic, discussing the game's background, its official availability on PC, and the legal/technical realities of "downloading" it. This can serve as a framework for a paper you might write yourself, focusing on game preservation, emulation, and copyright.
Sengoku Basara 3 Utage: Matsu - Ultimate Difficulty Part 1 [HD]