Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
thuc dan » thuc hanh, hoc dan, thuc vat
cua viet » hoa viet, cua vat, cua dieu
nang dai » nang dau, nang tai, lang dai
qua nham » qua nhat, qua cham, sua nham
so sach » so sanh, bo sach, co sach
ca viet » va viet, co viet, hoa viet
thuc va » thuc vat, thuc day
dai hoi » dai hoc, dai hai, dai moi
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach v nang dai hoi. hieu qua nham ((thuc va) OR (thuc dan)) thanh vai ((cua viet) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach v nang dai hoi. hieu qua nham ((thuc va) OR (thuc dan)) thanh vai ((cua viet) OR (ca viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach v nang dai hoi. hieu qua nham ((thuc va) OR (thuc dan)) thanh vai ((cua viet) or (ca viet))".
• Adding a wildcard symbol may retrieve word variants: so sach v nang dai hoi. hieu qua nham ((thuc va) OR (thuc dan)) thanh vai ((cua viet) or (ca viet))*.