Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nang cai » nang cao, nang tai, nang cap
thai cua » than cua, tai cuc, tri cua
sang tao » hang tai
ban hanh » ban hang
va hanh » van hanh, va thanh, va danh
vu sach » vu bach, su sach, vu khach
nam luc » nang luc, nhan luc, nam thuc
sach ky » sac ky, sach y, sach ty
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: vu sach ky ((nang cai) or (sang tao)) hoi. hieu van nam luc ((va hanh) or (ban hanh)) thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky ((nang cai) OR (sang tao)) hoi. hieu van nam luc ((va hanh) OR (ban hanh)) thai cua tre.
• Adding a wildcard symbol may retrieve word variants: vu sach ky ((nang cai) or (sang tao)) hoi. hieu van nam luc ((va hanh) or (ban hanh)) thai cua tre*.