Looking for original source for this sheet music (心のたからばこ)

[AlphaRomeo]

Im trying to find the original source for this sheet music so I can buy it. Can anyone help me find it?

[Dekkadeci]

Can't pinpoint which book right now, but that page alone gives crucial hints: the sheet music is for "Diamonds in My Heart", and this theme is from the video game Chocobo Racing.

[AlphaRomeo]

Yeah, the copyright also shows 1999  Solid Co. Ltd but I cant any information about that company or their products.

[AlphaRomeo]

found it, ISBN 4773234237. unfortunately, it is very difficult to find.