1. Fortune Business Insights Excavators market size share and industry analysis by type (mini/compact excavator crawler excavator wheeled excavator other excavator) by end-use industry (construction forestry agriculture mining others) and regional forecast 2019–2026 (2019); www.fortunebusinessinsights.com/industry-reports/excavators-market-100861.
2. Grand View Research Excavator market size share trends analysis report by product (crawler wheeled mini/compact) by application (construction) by region competitive landscape and segment forecasts 2018–2025 (2018); www.grandviewresearch.com/industry-analysis/excavators-market.
3. IndustryResearch Global Excavator Market Report (2020);https://industryresearch.co/-global-excavator-market-15473051.
4. S. Afanuh M. Gillen T. Lentz Preventing worker deaths from trench cave-ins;https://cdc.gov/niosh/docs/wp-solutions/2011-208/pdfs/2011-208.pdf?id=10.26616/NIOSHPUB2011208.
5. Occupational Safety and Health Administration Excavation: Hazard recognition in trenching and shoring. (OSHA technical manual 1999).