The phrase "accessed only by" is correct and usable in written English.
It can be used to specify that something is available exclusively to certain individuals or groups.
Example: "The confidential files can be accessed only by authorized personnel."
Alternatives: "available solely to" or "restricted to".
It also has its own quay and moorings and can be accessed only by footpath or boat.
Usually, Mr. Bailey said, that is done by using locked mailboxes that can be accessed only by tenants and postal workers.
One chapel is accessed only by a ladder up a rock face, others are tucked inside natural niches or at the foot of huge crags.
The lower bowl of the stadium can be accessed only by forking over ludicrous sums of money to the ticket office.
Some are remote, cutting-edge, autonomous, space-age pods accessed only by risky ascents in technical gear; others you can go and see in your flip-flops.
Surrounded by a high wire fence, and accessed only by a huge steel security gate, it is a vast site that took me an afternoon to wander through.
We ride the elevator in respectful silence to the second floor, which can be accessed only by the turn of a key on Mickey's key chain.
We already have sex offender registers in Australia, mostly for child abusers, but they can be accessed only by the police, not the public.
If it is neither, it may be accessed only by the most cautious people who wouldn't risk their pension pots anyway.
"And I said, 'I don't know that music.' And he said, 'Wally, you're gonna love this.' " Years later, De Backer wrote a tribute song for Perrey, using an Ondioline he could access only by flying from Melbourne to the Audities Foundation, an electronic-instruments archive in Calgary, Canada.
The bus can establish Internet access only by stringing a telephone cord to a telephone jack nearby.
