Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Oxygen Metallicity Determinations from Optical Emission Lines in
  Early-type Galaxies
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph