Perhaps you should try some spelling variations:
thuoc sach » nuoc sach, thuat sach, thuoc sinh
toc sach » doc sach, nuoc sach, toc san
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
nam truc » nam truoc, nam thuc, nam trung
hanh tai » thanh tai, hang tai, han tai
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
cuc te » cua te, cuc thue, cuc tieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((((toc sach) OR (thuoc sach))) or (hoc sach)) ky dang xa hoi. hieu van nam truc va hanh tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((toc sach) OR (thuoc sach))) OR (hoc sach)) ky dang xa hoi. hieu van nam truc va hanh tai cuc te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((toc sach) OR (thuoc sach))) or (hoc sach)) ky dang xa hoi. hieu van nam truc va hanh tai cuc te".
• Adding a wildcard symbol may retrieve word variants: ((((toc sach) OR (thuoc sach))) or (hoc sach)) ky dang xa hoi. hieu van nam truc va hanh tai cuc te*.