Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
viec cac » vien cac, viec cua, viec lam
cac truc » cau truc, cac tru, cac trung
lang dai » lang hai, lang mai, lang chai
tu sach » thu sach, su sach, te sach
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
truc va » thuc va, thuc vat, trung va
va lang » va nang, hoa lang
cua tu » cua tuc, cua su, cua cu

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) or (thu hoach)) ky ((nang ma) OR (sang ma)) hoa. hieu viec cac truc va lang dai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu hoach)) ky ((nang ma) OR (sang ma)) hoa. hieu viec cac truc va lang dai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu hoach)) ky ((nang ma) OR (sang ma)) hoa. hieu viec cac truc va lang dai cua tu".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu hoach)) ky ((nang ma) OR (sang ma)) hoa. hieu viec cac truc va lang dai cua tu*.