Perhaps you should try some spelling variations:
hoc khanh » hoc nhanh, hoc thanh, hoc hanh
khanh hoa » thanh hoa, hang hoa
thu sach » thuat sach, thuoc sach, thu hoach
cuu tong » cuu cong, cuu tinh, huu tung
tong hoc » tuong hoc, thong hoc, trong hoc
khoa dan » khoa dang, hoa dan, khoa can
gian dan » gian lang
tu sach » su sach, te sach, tu cach
hoc da » hoc dan, hoc dai, hoc dat

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) hoc tap, nghien cuu tong hoc khanh hoa hoc da khoa dan gian dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) hoc tap, nghien cuu tong hoc khanh hoa hoc da khoa dan gian dan.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) hoc tap, nghien cuu tong hoc khanh hoa hoc da khoa dan gian dan*.