In the top 20 is a "business" survival book. Number 5 on the list, in fact!
Also a dupe or two, as paperback and hardcover editions show up separately. I suppose the list is automated...
#8, "Wildwood Wisdom" by Ellsworth Jaeger, has long been a favorite of mine.
Also, IMHO #10, Neil Strauss' "Emergency" is of little or no use as a survival/prepping manual, it's a liberal's journey into prepping. Full of liberal elitist conceit. YMMV, get it from a library and check it out before buying.
Continuing on through the list, the further down you go the more duplicate titles there are; multiple editions or sellers, perhaps. Also, the more likely it is that the titles will be either a narrative, or a "lifestyle" guide.