This book has been frequently challenged due to its portrayal of Muslims.

The rival papers have frequently challenged each other's circulation claims.

But his fine work, which has been frequently challenged by fellow historians, does not remove the grounds for debate.

Most of them came to his defense in the years of 1831-33, when Cooper was frequently challenged by the state legislature.

Their music is meant to present audiences with entertainment that frequently challenges cultural suppositions.

Licensing schemes have been frequently challenged as encroaching on the federal power.

From 1660 to 1673, the Wicocomico frequently challenged colonists in court over land disputes.

The mercurial Balanchine was always unpredictable, and he frequently challenged himself.

Her focus is the woman's viewpoint, and frequently challenges the status quo in what has been a male-dominated society.

Conventional wisdom has it that the decision saved many lives in the long run, but this view has been frequently challenged.