Perhaps you should try some spelling variations:
trinh han » trinh quan
trinh vat » trinh van, trinh luat, sinh vat
hieu van » thien van, lieu va, hieu ve
hoc thuc » hoc huu
su sach » so sach, vu sach
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
ha hoi » hoa hoi, ha noi, xa hoi
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky lang ha hoi. ((hieu van) or (hieu va)) hoc thuc vat ((trinh vat) or (trinh han)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang ha hoi. ((hieu van) OR (hieu va)) hoc thuc vat ((trinh vat) OR (trinh han)) cua te.
• Adding a wildcard symbol may retrieve word variants: su sach ky lang ha hoi. ((hieu van) or (hieu va)) hoc thuc vat ((trinh vat) or (trinh han)) cua te*.