https://en.wikipedia.org/wiki/Chollima_Movement
Citation #2 points to a book that collates many sources. Here's what it has to say:
Show
Wikipedia is just a collection of opinions laundered by loosely-relevant citations appearing next to them (or in this case, completely irrelevant ones).
They didn't even need the "er" after "hard" in the quote, it exists only to make the unnecessary quote wrong