This document summarizes a systematic literature review on methods for software effort estimation. It identifies 74 relevant studies published between 2000-2017. The studies are classified based on publication channels, research approaches, contribution types, and techniques used. The review finds that eight types of techniques are commonly used for software effort estimation, including expert judgment, regression-based methods, and machine learning methods. It also analyzes factors that impact estimation accuracy, such as dataset quality, feature selection, and parameter optimization. The goal of the review is to provide an overview of the software effort estimation field and techniques used to improve accuracy.