Scripta Sinica = 漢籍電子文獻資料庫 (Hànjí diànzǐ wénxiàn zīliào kù) [via Academia Sinica]
This is a large full-text collection of classics pertaining to Chinese history. Use the 授權使用 button to access the full (licensed) collection.
The creators of this database describe it as a project “to digitize all documents essential to research in traditional Sinology. . . .”