Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
khang te » khang tiet, hang tu, khang a
thuc van » thuc vat, thuc dan, thuc hanh
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
vu sach » vu bach, su sach, vu khach
van hau » van ha, van hai, van dau
ma hoi » mai hoi, xa hoi, ma hoa
te cua » tue cua, le cua, de cua

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 (vu sach)) ky nang ma hoi. hieu van hau ((thuc van) OR (thuc va)) khang te cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu sach)) ky nang ma hoi. hieu van hau ((thuc van) OR (thuc va)) khang te cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (vu sach)) ky nang ma hoi. hieu van hau ((thuc van) OR (thuc va)) khang te cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu sach)) ky nang ma hoi. hieu van hau ((thuc van) OR (thuc va)) khang te cua triet*.