Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thuc dan » thuc hanh, hoc dan, thuc vat
thi hanh » thi thanh
thi nang » thi cong, ki nang
hanh tai » thanh tai, hang tai, hinh tai
cam thuc » am thuc, nam thuc, cam thu
han tai » hang tai, nhan tai, van tai
tu sach » thu sach, su sach, te sach
ca hoi » cau hoi, cua hoi, xa hoi
va cam » va cham, va cac, va cao

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 ((thi hanh) or (thi nang)) ca hoi. lieu va cam thuc dan ((hanh tai) OR (han tai)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((thi hanh) OR (thi nang)) ca hoi. lieu va cam thuc dan ((hanh tai) OR (han tai)) cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((thi hanh) or (thi nang)) ca hoi. lieu va cam thuc dan ((hanh tai) OR (han tai)) cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((thi hanh) or (thi nang)) ca hoi. lieu va cam thuc dan ((hanh tai) OR (han tai)) cua viet*.