小乌讲到布莱恩所见到的南极附近那个直升机可以飞进去的巨大洞口时,不禁让人想起上个世纪美国探险家Admiral Richard E. Byrd从极地大洞口飞进去的事情,有一本书可供参考:The hollow earth, the greatest geographical discovery in history made by Admiral Richard E. Byrd in the mysterious land beyond the poles, the true origin of the flying saucers