^[a-zA-Z]+(['.]?\s*[a-zA-Z]+)*$

##</code><code>##

St.John's high school.
A. B. C. school.
Institute of management.
oxford university.
A.B.C college.
Ragu ram's college of technology.

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A..B.C college.
St.John''s high school.
St.John'.'s high school.