I've read in most places that the minimum number of flips in the worst case scenario required to sort a stack by any algorithm is between $15n/14$ and $18n/11$. But I read here:
It was shown in the mid-1990s that we can sort any permutation (stack of unburnt pancakes) in $n-1$ reversals
that it's $n-1$. Is this wrong or have I misinterpreted the two results? Where can I see this 1990's paper which showed that it was $n-1$?