Duxiu 读秀 
http://uclibs.org/PID/156553
More than 1.4 million full-text books
Currently available -- full-text searches, tables of content, and first 17 pages of select books. Forward purchase suggestions to Xi Chen, xichen031@ucsd.edu
Chinamaxx Digital Libraries 中文电子书集献 http://uclibs.org/PID/35493
Also known as Chinamaxx Digital Library of Chinese E-Books, and SuperStar Digital Libraries
地方志 http://uclibs.org/PID/220727
人民画报 http://uclibs.org/PID/220726
文史资料 http://uclibs.org/PID/220728
Encyclopedia of Taiwan 臺灣文獻叢刊 http://uclibs.org/PID/113713
Also known as the Encyclopedia of Taiwan; contains search-able full-text and scanned images of 595 books originally published in print between 1959 and 1972; temporal coverage from the Tang Dynasty to the Japanese occupation period
Local histories, official documents of the Ming-Qing and Nan-Ming Dynasties
Ariti E-Books 华艺中文电子书 http://uclibs.org/PID/254659
It provides access to Chinese ebooks primarily published in Taiwan, Hong Kong and Macau. It covers subjects such as philosophy, religion, natural sciences, applied science, social sciences, history, geography, language and linguistics, and literature and arts.
HathiTrust Digital Library http://www.hathitrust.org
An increasingly comprehensive digital archive of library materials converted from print that is co-owned and managed by a number of academic institutions. More than 50 partners, including all UC campuses
UC Press E-Books Collection, 1982-2004, includes almost 2,000 books from academic presses on a range of topics, including art, science, history, music, religion, and fiction.
ACLS Humanities E-Book (HEB) is an online collection of nearly 4,700 books of high quality in the humanities.
Full text books provided by JSTOR.
