Matched context for reversal and perturbation

The page lists matched contexts for reversal and perturbation.

Share - reversal	Share - perturbation	Phrase
11.95%	4.23%	{reversal or perturbation} frequency
2.14%	5.85%	ratio {reversal or perturbation}
4.89%	2.26%	{reversal or perturbation} number
2.15%	4.00%	{reversal or perturbation} [does] occur
1.04%	7.08%	pressure {reversal or perturbation}
1.54%	3.81%	cause {reversal or perturbation} [perform operation]
0.82%	2.04%	prevent {reversal or perturbation} [perform operation]