Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
dan hanh » dang hanh, dan khanh, dan thanh
toc sach » hoc sach, doc sach, thuoc sach
thuc dan » thuc hanh, hoc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
su sach » vu sach
tai cua » thai cua, tai cuc, tri cua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
so sach » so sanh, bo sach, co sach
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: ((((su sach) OR (so sach))) or (toc sach)) ky lang xa hoi. hieu van nam thuc dan hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((su sach) OR (so sach))) OR (toc sach)) ky lang xa hoi. hieu van nam thuc dan hanh tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((su sach) OR (so sach))) or (toc sach)) ky lang xa hoi. hieu van nam thuc dan hanh tai cua tre*".