Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
danh sai » dung sai, danh bat, danh dau
vat danh » va danh, van danh, luat danh
van nham » van nam, van nhan, van tham
hieu van » hieu va, thien van, lieu va
sai cua » dai cua, hai cua, lai cua
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
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: ((toc sach) or (hoc sach)) ((ky lang) OR (ky dang)) xa hoi. hieu van nham thuc vat danh sai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ((ky lang) OR (ky dang)) xa hoi. hieu van nham thuc vat danh sai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (hoc sach)) ((ky lang) OR (ky dang)) xa hoi. hieu van nham thuc vat danh sai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) ((ky lang) OR (ky dang)) xa hoi. hieu van nham thuc vat danh sai cua tre*.