1. Simple Project Estimation based on Requirements-Complexity: http://sanderstechnology.com/2014/a-simple-project-effort-estimation-utility/12854/#.WoRNYpPwYfM
  2. Agile Business Consortium Estimating Timelines: https://www.agilebusiness.org/content/estimating
  3. Best practices to estimate accurate ERP schedules, budgets in an ERP project: http://searcherp.techtarget.com/feature/Best-practices-to-estimate-accurate-ERP-schedules-budgets-in-an-ERP-project

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