This document summarizes research on quality assurance in requirement engineering. It discusses 22 research papers on analyzing different quality parameters to ensure high quality requirements. The major quality parameters discussed include feasibility, comprehensibility, modifiability, completeness, correctness, and structure. Several models and techniques are proposed for checking requirements quality, such as the LaQuSo model, ontology, case-based reasoning, and artifact-based approaches. Ensuring requirements quality is important as it can significantly reduce costs from defects in later stages of development.