Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Academic collaboration rates and citation associations vary
  substantially between countries and fields
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol