Perhaps you should try some spelling variations:
vai thiet » va thiet, tai thiet, van thiet
thanh va » thanh van, hanh va, thanh ha
va thanh » gia thanh, ban thanh, va tinh
qua cac » cua cac
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach
qua cam » qua cham, qua ca, qua cai
cong ha » cong hoa, dong ha, cong tac
vu sach » vu bach, vu khach
ha hoi » hoa hoi, ha noi, xa hoi
va vai » va bai, va van, va dai

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 (vu sach)) tai cong ha hoi. hieu ((qua cam) OR (qua cac)) thuc va thanh va vai thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) tai cong ha hoi. hieu ((qua cam) OR (qua cac)) thuc va thanh va vai thiet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) tai cong ha hoi. hieu ((qua cam) OR (qua cac)) thuc va thanh va vai thiet*".