The phrase "are in a single" is correct and usable in written English.
It can be used when referring to items or elements that exist or occur within one unit or category.
Example: "The results of the experiment are in a single report that summarizes all findings."
Alternatives: "are contained in one" or "are found in a single".
We have been dealing with TimeSignature objects that are in a single Stream.
Most are in a single hand, probably that of Sebastianus Einhart.
Almost forty per cent are in a single age band of 15-24.
All the tempera-on-hardboard paintings, along with Lawrence's spare narrative texts, are in a single large room.
The residences, all 1,775 square feet, are in a single four-story building just across a coastal highway from white-sand beaches.
Israelis and Palestinians are in a single geographic state controlled by one government, but they live under two separate and unequal systems of rights and laws.
The top 64 players are in a single-elimination tournament that takes place over five days with 18-hole matches and a 36-hole final.
A disquieting voice occupies my brain: "Hey, idiots, you are in a single-engine plane, over an extremely cold lake 80 miles wide!
The IEEE 802.15.5 standard in [9] identifies that the MPNCs which are in a single-hop transmission range of each other need to synchronize their boundaries to a common ref-MPNC to avoid time slot overlaps due to synchronization issues.
Studies show that women are better learners when they are in a single-gender environment.1 A woman is twice as likely to ask questions, speak up and participate more when she is in a class of other female students, which means she learns more because the long-standing barriers for women are lifted.
It is assumed that most genes are in a single-copy dose in a genome and sequences of duplicated genes are usually diverged to such an extent that most of their reads do not cluster together.
