Please update the link of Visualizing word frequencies: [Visualizing word frequencies](https://nbviewer.jupyter.org/github/amanchadha/coursera-natural-language-processing-specialization/blob/master/1%20-%20Natural%20Language%20Processing%20with%20Classification%20and%20Vector%20Spaces/Week%201/C1W1_L2_Visualizing%20word%20frequencies.ipynb)
