https://calisphere.org/item/ark:/13030/tf1199p19x/
http://www.ronhenggeler.com/History/yerba_buena/1846-47.htm
https://calisphere.org/item/ark:/13030/tf867nb7vw/
http://www.ronhenggeler.com/History/yerba_buena/1851.htm
http://foundsf.org/index.php?title=Portsmouth_Square:_The_Plaza
http://www.ronhenggeler.com/History/yerba_buena/1851map.htm
Georeferenced Map 1: 1853 waterfront compared to 2016 San Francisco:
http://rumsey.georeferencer.com/map/KkCmRZpyKiDWTVkUoqeknb/201501160455-fApGQ1/visualize
Georeferenced Map 2, showing 1857 waterfront and 2016 San Francisco:
http://rumsey.georeferencer.com/map/xdHMjGyhMj2O9A57aZZxie/201411012317-O83u9b/visualize
Online articles
http://www.sfgate.com/news/article/Bones-found-at-Transbay-Transit-construction-site-5267803.php
http://foundsf.org/index.php?title=WILLIAM_RICHARDSON_AND_YERBA_BUENA_ORIGINS
http://www.sfgate.com/bayarea/article/Monumental-Man-Sausalito-memorial-erected-for-2939517.php
https://afsanfrancisco.files.wordpress.com/2012/03/vioget-the-first-survey-and-map-of-yerba-buena.pdf
http://www.sfgate.com/default/article/1st-S-F-civic-improvement-Yerba-Buena-footbridge-4649647.php#photo-4884791
http://www.sfgenealogy.com/sf/history/hbbeg15.htm
http://vm136.lib.berkeley.edu/BANC/collections/chineseinca/sfchinatown.html
http://www.sfmuseum.org/hist1/index2.html
http://www.emperorsbridge.org/