Clue: Literary doctor regularly phones about earlier unfinished work (7)
Answer: JOHNSON
Explanation: Literary doctor regularly phones about earlier unfinished work (7)
[*regularly*] (p)**H**(o)**N**(e)**S** + **ON** ("about") with **JO**(b) (*unfinished* "work" *earlier*) 
Refers to Dr Samuel Johnson, the 18th century writer who compiled a popular early dictionary of the English language.