Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thuc dan » thuc hanh, hoc dan, thuc vat
hieu van » hieu va, thien van, hieu ve
truc va » thuc va, thuc vat, trung va
vu sach » vu bach, su sach, vu khach
nang ma » tang ma, sang ma, nang cao
sach v » sach va, sach y, sach 2
ma hoi » mai hoi, xa hoi, ma hoa
v nang » va nang, vu nang, van nang
vi cua » vai cua, di cua

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 v nang ma hoi. ((hieu van) OR (lieu va)) cam ((truc va) or (thuc dan)) hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach v nang ma hoi. ((hieu van) OR (lieu va)) cam ((truc va) OR (thuc dan)) hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach v nang ma hoi. ((hieu van) OR (lieu va)) cam ((truc va) or (thuc dan)) hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: vu sach v nang ma hoi. ((hieu van) OR (lieu va)) cam ((truc va) or (thuc dan)) hanh vi cua viet*.