Perhaps you should try some spelling variations:
nang tao » nang cao, sang tao, nang tai
hieu van » thien van, lieu va
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
tao hoi » tao khoi, tao boi, tay hoi
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
dan hai » doan hai, dang hai, dan khai
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau

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 ky nang tao hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) cac xuc va dan hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang tao hoi. ((((hieu ve) OR (hieu van))) OR (hieu va)) cac xuc va dan hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang tao hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) cac xuc va dan hai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang tao hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) cac xuc va dan hai cua tre*.