Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
tinh va » tich va, trinh van, trinh vat
va tinh » may tinh
thuc va » thuc vat, thuc dan, thuc day
van cam » van nam, van lam, van cau
su sach » so sach, vu sach
ty hang » ly hang, thi hang, thu hang
ty nang » ky nang, ly nang, ty nong
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

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 ((((ty nang) OR (ty hang))) or (ty xang)) xa hoi. hieu van cam thuc va tinh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((((ty nang) OR (ty hang))) OR (ty xang)) xa hoi. hieu van cam thuc va tinh va cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((((ty nang) OR (ty hang))) or (ty xang)) xa hoi. hieu van cam thuc va tinh va cua tre*".