Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
tinh hai » tinh thai, tinh chat, trinh han
tinh bai » tinh bac, hinh bai, tinh bao
nhan luc » nang luc
hieu ve » hieu va, hieu van
ve nhan » ve nha, de nhan, va nhan
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
luc va » duc va, tuc va, loc va
ca tre » ca tren, cua tre, ca tru

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

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