beijing chinese importers foreign publications must verify products legal china say friday weeks british academic publisher block access hundreds scholarly article country reposted material cambridge university press cup say august remove 300 paper book review publish china quarterly journal website china follow request chinese government say block article cover sensitive topics include 1989 tiananmen square democracy protest 1960s cultural revolution tibet order keep academic educational materials available country move spark outcry academics attack decision affront academic freedom cup publish arm britain elite cambridge university late reverse decision reposted article china state council information office respond fax two weeks reuters request comment say publishers choose import materials base market demand law publications import china market must adhere chinese laws regulations publication importers responsible check content import publications say without elaborate mention cup time china education ministry foreign ministry cyberspace administration state publish authority decline comment rule communist party efforts censor news information sometimes backfire leave outsiders perplex 2009 software design check pornographic violent image pcs block image movie poster cartoon cat garfield dish flesh-colour cook pork one search engine close-up film star johnny depp face president xi jinping beijing step censorship tighten control internet various aspects civil society reassert party authority academia institutions weeks row academic article china say import publications must legal