Given the task definition and input, reply with output. In this task you need to indicate the required knowledge type to solve the pronoun coreference relations. Each of the provided inputs contains a sentence with a target pronoun and a question about the knowledge needed to solve the coreference relation between a noun phrase and the target pronoun. The resolution of the pronoun coreference relations typically involves one or multiple following knowledge types about commonsense: First: 'Property', the knowledge about property of objects (e.g., ice is cold). Second: 'Object', the knowledge about objects (e.g., cats have ears). Third: 'Eventuality', the knowledge about eventuality (e.g., 'wake up' happens before 'open eyes'). Forth: 'Spatial', the knowledge about spatial position (e.g., object at the back can be blocked). Fifth: 'Quantity', the knowledge about numbers (e.g., 2 is smaller than 10). Sixth: all other knowledge if above ones are not suitable. Write one or more correct categories. Output 'Others' if there is no category that fits well. 

Sentence: Many people start to read Paul's books and can't put them down. They are gripped because Paul writes so well. The 'They' refers to people. 
 Question: What is the knowledge type needed to solve this relation?

Others