Perhaps you should try some spelling variations:
thien van » thi van
hoc sach » hoc sinh, hoc cac, hoc anh
tinh bac » tinh cach, tinh hoc, tinh lao
tinh bai » tinh hai, hinh bai, tinh bao
nhan luc » nang luc
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
ca tren » cau tren, cu tren, la tren
luc va » duc va, tuc va, loc va

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