9[1]Miller G A.The Magical Number Seven,Plus or Minus Two:Some Limits on Our Capacity for Processing Information [ J ].Psychological review,1956 (63) 81-90
10[2]Craik F I.M.& Tulving E.Depth of Processing and the Retention of Words in Episodic Memory[ J].Journal of Experimental Psychology:General,1975 (104) 268-294