Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thuc van » thuc vat, thuc dan, thuc hanh
thuc va » thuc vat, thuc dan, thuc day
van cac » van hac, van cau, van bac
vu sach » vu bach, vu khach
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
su sach » so sach
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (su sach)) ky dang xa hoi. hieu van cac ((thuc van) OR (thuc va)) hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (su sach)) ky dang xa hoi. hieu van cac ((thuc van) OR (thuc va)) hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (su sach)) ky dang xa hoi. hieu van cac ((thuc van) OR (thuc va)) hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (su sach)) ky dang xa hoi. hieu van cac ((thuc van) OR (thuc va)) hanh vi cuu tre*.