1249
He is best known for his 1936 book , The Problem of Hamlet ( London : MacMillan ) , which makes a number of controversial arguments about Hamlet -- arguing , for example , that the play was written around 1588-89 ( rather than twelve years later , as most scholars insist ) , and that the so-called Ur-Hamlet , to which frequent allusion occurs starting in 1589 , is actually an early draft of Shakespeare 's play .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None