The discussion centers on the search for lecture notes or alternative texts that closely follow "Classical Mechanics" by Goldstein, particularly due to perceived conceptual errors in Goldstein's treatment of nonholonomic constraints. Participants express concerns about the mathematical rigor of Goldstein and similar texts, suggesting that they may not meet the standards expected by mathematicians. Arnold's "Mathematical Methods of Classical Mechanics" is recommended as a more rigorous alternative, while Lemos' "Analytical Mechanics" is praised for its clarity, numerous examples, and effective treatment of constraints. Specific flaws in Goldstein's work are highlighted, including issues with the Hamilton principle and the treatment of infinitesimal work done by friction. Overall, the conversation emphasizes the need for more rigorous and accessible resources in classical mechanics, particularly for those struggling with Goldstein's text.