The phrase "and only one course" is correct and usable in written English.
It can be used to specify that there is a singular option or path available in a given context.
Example: "After reviewing all the possibilities, we concluded that there was and only one course of action we could take."
Alternatives: "and just one option" or "and a single path".
With the adviser's approval, one, and only one, course from another institution, including Barnard, may be applied toward the psychology portion of the Neuroscience and Behavior major.
The authorization lasts for one quarter only and only one course may be dropped.
In more than a quarter of the courses, students using open textbooks achieved higher grades, and only one course using open textbooks showed lower grades (which is at least partially explained by the course's significantly higher completion rate, which includes the grades of students who would have otherwise dropped out).
A restricted block randomisation was performed as described elsewhere (Altman, 1991) to keep the number of patients close for both groups, and only one course of each patient was taken to avoid bias as a result of potential cumulative effects and to keep the observations independent.
Only one course on Evaluation of Outcomes of Information and Library Use and two courses on local resources.
It is clear, though, that Vichai and Aiyawatt were no longer willing to tolerate Pearson being in charge of their football club and that there was only one course of action in their eyes.
I noted before that in 1895 there was only one course offered on American literature.
Evrard Somda, the commander of Burkina Faso's specialist anti-terrorism squad, reached Avenue Kwame Nkrumah in the centre of Ouagadougou, the west African nation's capital, at about 8.30pm on Friday and realised immediately there was only one course of action.
I, myself, have been holding off on buying this little guy due to the $30+ price tag, the fact that there's only one course, and the relatively mediocre user reviews.
General oedema and capillary vasculitis in the lower legs occurred in one patient at level three, and this patient therefore received only one course of therapy.
Students may enroll for only one course per semester, and they must register and pay applicable fees at Berkeley.
