문서의 이전 판입니다!
http://theopentutorials.com/tutorials/android/dialog/android-download-multiple-files-showing-progress-bar
http://itmining.tistory.com/7
http://stackoverflow.com/questions/11585226/use-asynctask-to-load-bitmap-images
http://stackoverflow.com/questions/21061811/use-an-async-task-for-a-bitmap
http://hashcode.co.kr/questions/2310/%ED%94%84%EB%A1%9C%EA%B7%B8%EB%9E%98%EC%8A%A4%EB%B0%94-%EC%BB%A4%EC%8A%A4%ED%84%B0%EB%A7%88%EC%9D%B4%EC%A7%95%ED%95%98%EA%B8%B0