Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Point-contact studies of high-temperature superconductor $\rm
  YBa_2Cu_3O_{7-\delta}$
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph