Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The Millennium Arecibo 21-cm Absorption Line Survey. III. Techniques for
  Spectral Polarization and Results for Stokes V
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat