Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Direct observation of double valence-band extrema and anisotropic
  effective masses of the thermoelectric material SnSe
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an