"conducted only by" is correct and usable in written English.
You can use it to describe a process or activity that was conducted by a single person or force. Example: The training session was conducted only by the senior member of staff.
Usually, the hearings are conducted only by a staff hearing officer.
The Chinese government in recent years has allowed genetic research on the mummies to be conducted only by Chinese scientists.
A spokeswoman for the Hong Kong police said arrests of people wanted by overseas jurisdictions could be conducted only by local police forces.
Because there was as yet no Senate, the election was conducted only by the Chamber of Deputies, thus contravening the republic's new constitution.
However, in this country, major memory processing with E.M.D.R. therapy should be conducted only by a licensed therapist who has had training approved by the E.M.D.R. International Association (www.emdria.org), an independent professional association that sets the standards for all E.M.D.R. therapy training conducted in the United States.
These include demands that the agreement be binding, that all detention operations be turned over rapidly to the Afghan government, and that military night raids, which are central to American counterinsurgency tactics but a driving instigator of domestic outrage, be conducted only by Afghan forces.
Post hoc testing (contrast) was conducted only when preceded by significant analysis of variance effects.
Identifiers were used for record linkages only, and conducted solely by state staff and not affixed to the survey or administrative responses.
The subscription season's roster of guest conductors includes significant names, but they are conducting only two works by living composers, one from 1988 and the other from 1966: semi-new new music, at best.
Although single creatinine measurement is considered appropriate for epidemiologic studies, by conducting only a one time screening, we may have overestimated the CKD prevalence in Iran.
For, the Kantian can argue, if we are to treat another 'as an end', with the respect due to her as a rational and responsible agent, we must seek to modify her conduct only by offering her good and relevant reasons to modify it for herself.
