Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
thuat hoa » thuat toan, thuyet hoa, thuat do
chat hoa » chat va, chat huu, cau hoa
tu sach » thu sach, su sach, te sach
thuc va » thuc vat, thuc dan, thuc day
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
thai va » thai van
y nang » ky nang, ly nang, v nang
tuc va » truc va, tuc xa, duc va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang ((chat hoa) OR (thuat hoa)). hieu vu cham ((tuc va) or (thuc va)) hanh thai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((chat hoa) OR (thuat hoa)). hieu vu cham ((tuc va) OR (thuc va)) hanh thai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((chat hoa) OR (thuat hoa)). hieu vu cham ((tuc va) or (thuc va)) hanh thai va thiet".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((chat hoa) OR (thuat hoa)). hieu vu cham ((tuc va) or (thuc va)) hanh thai va thiet*.