Simplify the following text for a Grade 6 native English-speaking person.
Original: The Picture of Dorian Gray is the only published novel by Oscar Wilde , appearing as the lead story in Lippincott 's Monthly Magazine on 20 June 1890 , printed as the July 1890 issue of this magazine .
Simplified: The Picture of Dorian Gray is the only published book written by Oscar Wilde . It was first published in Lippincott 's Monthly Magazine on June 20 , 1890 .