At least 11 of the Nancy Drew books were printed in Asia, probably in Taiwan and during either the 1970s or 1980s. These books are pirated editions. I have eight of these books.
Most of the books have the black and white multi endpapers. One book has light brown instead of black on the endpapers.
The cover art has the appearance of color photocopies of the original cover art of the Grosset and Dunlap editions. The colors and image quality are off slightly. Below, I have photographed two of the pirated editions, seen on the left, and two of the Grosset and Dunlap editions, seen on the right.
You should be able to clearly see that Ski Jump looks to be a bad reproduction of the original cover.
The inside of each book is exactly the same as the Grosset and Dunlap edition, except for the copyright page. Asian characters have been added to each copyright page.
These books have always mystified me, since I have never understood why someone would pirate Nancy Drew books. It now occurs to me that perhaps the books could be offered less expensively to buyers in Asia by pirating the books than they could by importing the books from the United States. In any case, these books make for an interesting variant for people who collect Nancy Drew books.