Perhaps you should try some spelling variations:
dat thanh » dao thanh, dat khanh, dang thanh
day thanh » dao thanh, da thanh, dam thanh
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
doi cua » dai cua, hoi cua, dong cua
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 ky nang xa hoi. hieu van nam thuc ((day thanh) OR (dat thanh)) doi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. hieu van nam thuc ((day thanh) OR (dat thanh)) doi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu van nam thuc ((day thanh) OR (dat thanh)) doi cua tre*.