Perhaps you should try some spelling variations:
thien van » thi van
hoc sach » hoc sinh, hoc cac, hoc anh
tinh bai » tinh bac, tinh hai, hinh bai
nhan luc » nang luc
va tinh » may tinh
ca tren » cau tren, cu tren, la tren
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
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) OR (nang ma)) hoi. ((hieu ve) or (thien van)) nhan luc va tinh bai ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky ((nang xa) OR (nang ma)) hoi. ((hieu ve) OR (thien van)) nhan luc va tinh bai ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky ((nang xa) OR (nang ma)) hoi. ((hieu ve) or (thien van)) nhan luc va tinh bai ca tren".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky ((nang xa) OR (nang ma)) hoi. ((hieu ve) or (thien van)) nhan luc va tinh bai ca tren*.