Perhaps you should try some spelling variations:
sach trien » sach tien, sach tren, sach thieu
trien khat » trien khai, trien thuat, trien nha
sach vien » sach tien, sach viet, mach dien
khat khoa » khuan khoa, pham khoa, vat khoa
noi khoa » ngoai khoa, hoc khoa, tai khoa
khoa hoc » hoa hoc
vu sach » vu bach, su sach, vu khach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( doc ((sach vien) OR (sinh vien)) noi khoa hoc ) or ( vu sach trien khat khoa hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( doc ((sach vien) OR (sinh vien)) noi khoa hoc ) OR ( vu sach trien khat khoa hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( doc ((sach vien) OR (sinh vien)) noi khoa hoc ) or ( vu sach trien khat khoa hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( doc ((sach vien) OR (sinh vien)) noi khoa hoc ) or ( vu sach trien khat khoa hoc ))*.