Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: PKN problem for non-Newtonian fluid   The paper presents analytical solution for hydraulic fracture driven by a
non-Newtonian fluid and propagating under plane strain conditions in cross
sections parallel to the fracture front. Conclusions are drawn on the influence
of the fluid properties on the fracture propagation.

7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph