It seems there are some typographical errors in your statements about cellular respiration, but I can help clarify them. Here's a combination of corrected statements and explanations:
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Cellular respiration has three stages: This is correct. The three stages are glycolysis, the citric acid cycle (Krebs cycle), and the electron transport chain.
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The greatest amount of ATP is generated during the citric acid cycle: This is incorrect. The greatest amount of ATP (or its equivalent in terms of reducing equivalents) is produced during the electron transport chain, not the citric acid cycle. The citric acid cycle produces a small amount of ATP directly through substrate-level phosphorylation, but most ATP is produced during oxidative phosphorylation in the electron transport chain.
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Glycolysis is a stage common to both aerobic and anaerobic cellular respiration: This is correct. Glycolysis occurs in both types of respiration, regardless of the presence of oxygen.
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The electron transport chain has a direct requirement for oxygen: This is also correct. The electron transport chain relies on oxygen as the final electron acceptor in aerobic respiration.
Given these statements, the incorrect one is: "The greatest amount of ATP is generated during the citric acid cycle."