Fundamentals of Data Visualization, Claus O. Wilke, 2019 (O'Reilly Media) - A comprehensive guide to creating effective data visualizations, with a specific section on the appropriate use and interpretation of bar charts for categorical data.
seaborn.countplot - seaborn 0.13.0 documentation, Michael Waskom and the Seaborn development team, 2024 - Official documentation for Seaborn's countplot function, detailing its parameters and usage for visualizing the frequency distribution of categorical data.
Visualization - pandas 2.2.0 documentation, The Pandas Development Team, 2024 - The official Pandas user guide section on visualization, illustrating how to generate bar charts directly from Series or DataFrames using the .plot() method.