Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
thuc dan » thuc hanh, hoc dan
vanh dai » van dai, vanh tai, lanh dao
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va, hieu qua
va nham » va cham, va tham, va nha
thuc va » thuc day
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky dang xa hoi. hieu va nham ((((thuc va) OR (thuc vat))) or (thuc dan)) vanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky dang xa hoi. hieu va nham ((((thuc va) OR (thuc vat))) OR (thuc dan)) vanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky dang xa hoi. hieu va nham ((((thuc va) OR (thuc vat))) or (thuc dan)) vanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky dang xa hoi. hieu va nham ((((thuc va) OR (thuc vat))) or (thuc dan)) vanh dai cua tre*.