Fix two citations

docs/src/Combinatorics/partitions.md

@@ -23,8 +23,8 @@ num_partitions(::Oscar.IntegerUnion)
 > How many ways are there to pay one euro, using coins worth 1, 2, 5, 10, 20, 50, and/or 100
 > cents? What if you are allowed to use at most two of each coin? 
 
-This is Exercise 11 in [Knu11](@ref), Section 7.2.1.4 (page 408). It goes back to the famous
-"Ways to change one dollar" problem, see [Pol56](@ref). Generally, the problem is to
+This is Exercise 11 in [Knu11](@cite), Section 7.2.1.4 (page 408). It goes back to the famous
+"Ways to change one dollar" problem, see [Pol56](@cite). Generally, the problem is to
 generate and/or count partitions satisfying some restrictions. Of course, one could generate
 the list of all partitions of 100 (there are about 190 million) and then filter the result
 by the restrictions. But for certain types of restrictions there are much more efficient