Perhaps you should try some spelling variations:
thuc day » thuc dan, thuc vat
tu sach » thu sach, su sach, te sach
tinh de » tinh da, sinh de, tinh he
thuc va » thuc vat, thuc dan
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
dai hoi » dai hoc, dai hai, dai moi
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
de cua » le cua, te cua, dieu cua
va lap » va dap

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 ((ma hoi) or (dai hoi)). hieu va lap ((thuc va) OR (thuc day)) tinh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((ma hoi) OR (dai hoi)). hieu va lap ((thuc va) OR (thuc day)) tinh de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((ma hoi) or (dai hoi)). hieu va lap ((thuc va) OR (thuc day)) tinh de cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((ma hoi) or (dai hoi)). hieu va lap ((thuc va) OR (thuc day)) tinh de cua tre*.