Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » thien van, lieu va, hieu ve
cham luc » cham soc, nhan luc, cham cuu
tinh bai » tinh bac, tinh hai, hinh bai
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
luc may » truc may, phuc may
ca tre » ca tren, cua tre, va tre
tru » truc

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky nang xa hoi. ((hieu van) or (hieu va)) cham luc may tinh bai ((ca tre) OR (ca tru))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang xa hoi. ((hieu van) OR (hieu va)) cham luc may tinh bai ((ca tre) OR (ca tru)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang xa hoi. ((hieu van) or (hieu va)) cham luc may tinh bai ((ca tre) OR (ca tru))".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang xa hoi. ((hieu van) or (hieu va)) cham luc may tinh bai ((ca tre) OR (ca tru))*.