https://www.youtube.com/watch?v=7AZeTN4eCNM&t=382s
https://www.youtube.com/watch?v=8qDxqBvK3NA
https://rarehistoricalphotos.com/building-liberty-ships-1941/
https://link.springer.com/content/pdf/10.1007/s11837-015-1697-9.pdf
https://royalsocietypublishing.org/doi/10.1098/rspa.1921.0089
http://www.usmm.org/libertyships.html
https://military-history.fandom.com/wiki/Liberty_ship#In_popular_culture
https://www.brighthubengineering.com/marine-history/88389-history-of-the-liberty-ships/
https://www.marinelink.com/news/ducklings-steaming363512
https://www.nps.gov/articles/liberty-ships-and-victory-ships-america-s-lifeline-in-war-teaching-with-historic-places.htm
https://www.hmdb.org/m.asp?m=212672
https://dlg.usg.edu/collection/dlg_vsbg?link=vsbg&page=2
https://en.wikipedia.org/wiki/German_auxiliary_cruiser_Stier
https://en.wikipedia.org/wiki/Constance_Tipper
https://zh.wikipedia.org/wiki/%E8%87%AA%E7%94%B1%E8%BD%AE
