Perhaps you should try some spelling variations:
"yu de shi fang xue cong shu." » "yu de shi fan xue cong shu.", "yu de shi feng xue cong shu.", "yu de shi tang xue cong shu."
"yu de shi yang xue cong shu." » "yu de shi yong xue cong shu.", "yu de shi yan xue cong shu.", "yu de shi ying xue cong shu.", "yu de shi yang xie cong shu."
"yu da shi tong du cong shu." » "yu da shi cong du cong shu.", "yu da shi yong du cong shu.", "yu da zhi tong du cong shu.", "yu da shi tong yu cong shu.", "yu da shi tong su cong shu.", "yu da shi song du cong shu.", "yu da shi tong jiu cong shu.", "yu da shi tong lun cong shu.", "yu da shi tong shu cong shu.", "yu fa shi tong du cong shu."

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("yu de shi fang xue cong shu.") OR ("yu de shi yang xue cong shu."))) or ("yu da shi tong du cong shu."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("yu de shi fang xue cong shu.") OR ("yu de shi yang xue cong shu."))) OR ("yu da shi tong du cong shu.")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"yu de shi fang xue cong shu.\") OR (\"yu de shi yang xue cong shu.\"))) or (\"yu da shi tong du cong shu.\"))".
• Removing quotes may allow a broader search: (((( yu de shi fang xue cong shu. ) OR ( yu de shi yang xue cong shu. ))) or ( yu da shi tong du cong shu. )).
• Adding a wildcard symbol may retrieve word variants: (((("yu de shi fang xue cong shu.") OR ("yu de shi yang xue cong shu."))) or ("yu da shi tong du cong shu."))*.