Osama Sayed Osman Sayed e Abusamra Awad Attalemanan, THE STRUCTURAL PERFORMANCE OF TOWER CRANES USING COMPUTER PROGRAM SAP2000-v18, Sudan University of Science and Technology, 19 ottobre 2016. URL consultato il 12 novembre 2019 (archiviato dall'url originale il 14 dicembre 2019).
«The earliest recorded version or concept of a crane was called a Shaduf and used over 4,000 years by the Egyptians to transport water.»
