Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
hanh tai » thanh tai, hang tai, han tai
tu cach » tu cac
su sach » so sach, vu sach
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
thuc ve » thuc va, thuc te, thuc viet
ve hanh » ve thanh, ve canh, va hanh
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (su sach)) ky sang ma hoi. hieu van nam thuc ve hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (su sach)) ky sang ma hoi. hieu van nam thuc ve hanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (su sach)) ky sang ma hoi. hieu van nam thuc ve hanh tai cua tre*.