{'harappan culture': [1, 0, 1, 3], 'indus': [0, 0, 0, 1], 'causes': [1, 0, 0, 6], 'various causes': [0, 0, 0, 1], 'decline': [1, 0, 4, 11], 'floods': [1, 1, 0, 1], 'inundation': [0, 0, 0, 1], 'earthquakes': [2, 0, 0, 2], 'fertility': [5, 0, 1, 4]}