Stream Processing with Apache Flink, Fabian Hueske, Vasiliki Kalavri, 2019 (O'Reilly Media) - Explains Apache Flink's time semantics, Event Time, Processing Time, and Watermarks for consistent stream processing.
Event Time and Watermarks, The Apache Flink Community, 2024 - Official documentation explaining Event Time, Processing Time, and Watermarks in Apache Flink, covering their configuration and behavior.