References:
The Epic of Man by the Editors of LIFE (Norman Ross) - Time Incorporated - NY 1961
Communities of the Indus:
The remains of the world's third great civilization reveal a genius for big-city planning unrivaled in ancient times.The inhabitants of the Indus Valley could write, but we cannot decipher what little of their writing has been found.

The World's Last Mysteries by the Reader's Digest Association Limited - Paris 1976
The Land of the Queen of Sheba:
The Bible tells how the Queen of Sheba visited Jerusalem. For 30 centuries she has inspired a variety of legends. If she did exist she almost certainly came from Southern Arabia, where, in the scorching plains, remains of the ancient kingdom of Sheba are still visible today.

The World's Last Mysteries by the Reader's Digest Association Limited - Paris 1978
Digging up the past:
"It seems that mystery and imagination are as vital as reason for man in the hunt for truth. As Albert Einstein wrote in 1930: 'The most beautiful thing we can experience is the mysterious; it is the source od all true art and science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: his eyes are closed'."