The phrase "a firm control over" is correct and usable in written English.
It can be used when discussing authority, influence, or management of a situation, organization, or group.
Example: "The manager maintained a firm control over the project's progress to ensure timely completion."
Alternatives: "a strong grip on" or "a tight hold on".
Shahu has a firm control over the excited posse who follow him in the hope of becoming "one of the biggest drug dealing gangs of the town".
David DiMartino, a spokesman for the Democratic Senate Campaign Committee, said: "The difference this time is that Governor Nelson has a firm control over the campaign, which is staffed by some of the best political professionals in Nebraska.
During World War II the French colonial regime exercised a firm control over Bao Dai until the Japanese coup de force of March 1945, which swept away French administration in Indochina.
The polls reflect a deep mistrust about earlier commitments made by politicians to establish a "firm control over immigration".
A firmer control over the material might have prevented Pagford's inhabitants from being turned into a gallery of grotesques, with every character carrying a label: wife beater, drug addict, alcoholic, snob, gossip, fantasist and so on.
By the mid-1930s the British realized that Abd al-Rahman expected to be recognized as royalty, had firm control over a thriving Mahdist movement, and was actively seeking new adherents.
Nero swiftly took firm control over an unsettled public; all but Claudius' most rigid and unmoving supporters became Nero's men after only a short period.
Instead, they emerged with a two-game lead over the Bucks 28-300) and firm control over their destiny as they navigate the final eight games of the regular season.
As the child grows up to become an entrepreneur leader, s/he tend to create and exert firm control over their own businesses in order to overcome what might be considered a hostile and threatening world.
Perpetuating the same old policies enshrined Castro as a martyr to "American imperialism," and enabled him to exercise firm control over the Cuban nation.
But since Communist Party bosses usually have firm control over local police, courts and press, only a fraction of crimes may be reported in the controlled media.
