Perhaps you should try some spelling variations:
cua tren » dua tren, ca tren, cua tre
dang hai » dang khai, hang hai, dung hai
hai cua » thai cua, dai cua, hoi cua
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
su sach » vu sach
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » truc va, tuc xa, duc va
v nang » va nang, vu nang, van nang
va cau » van cau, va cac, va dau

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) or (so sach)) v nang ma hoi. hieu va cau ((tuc va) OR (thuc va)) dang hai cua tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) v nang ma hoi. hieu va cau ((tuc va) OR (thuc va)) dang hai cua tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) v nang ma hoi. hieu va cau ((tuc va) OR (thuc va)) dang hai cua tren*".