Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Magnetic oscillations and field induced spin density waves in
  (TMTSF)_2ClO_4
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga