SN4 ""

No	Pattern	Freq
1	[prep] the problem of	1394
2	[prep] the problem of	733
3	[prep] the problems of	661
4	to the problem of	427
5	to the problem of	427
6	of the problem of	304
7	of the problem of	304
8	with the problem of	273
9	with the problem of	273
10	on the problem of	83
11	on the problem of	83
12	about the problem of	61
13	about the problem of	61
14	in the problem of	42
15	in the problem of	42
16	by the problem of	31
17	by the problem of	31
18	from the problem of	29
19	from the problem of	29
20	for the problem of	23
21	for the problem of	23
22	into the problem of	19
23	into the problem of	19
24	at the problem of	18
25	at the problem of	18
26	despite the problem of	10
27	over the problem of	10
28	over the problem of	10
29	despite the problem of	10
30	round the problem of	8