Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Comments on: "Starting solutions for some unsteady unidirectional flows
  of a second grade fluid," [Int. J. Eng. Sci. 43 (2005) 781]
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex