Perhaps a lawsuit, based on the number of words that were plagarised. The proportion that were taken, without credit, would amount to a percentage of the total book. That total in relation to the sales price, full price always, would be the amount that would be due to the authors, their heirs, or the publishing house, that authored the book. Authors first, publishers last.

Losing money on a book would likely wake them up.

As a class action, there would be enough books, authors, etc., to generate enough fees, to make a lawyer salivate, perhaps. Definitely worth a go.

If in a thesis, term paper, automatically one full grade degraded. Without punishment, it will not stop.