Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
tinh thai » sinh thai, tinh toan, tinh chat
cua triet » cua viet, su triet, va triet
tinh tai » trinh tai, tinh hai, hinh tai
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
cac do » cac don, cac doi, cac du
do va » do van, so va

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 ky ((nang xa) or (nang x)) hoi. hieu va cac do va ((tinh tai) OR (tinh thai)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky ((nang xa) OR (nang x)) hoi. hieu va cac do va ((tinh tai) OR (tinh thai)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky ((nang xa) or (nang x)) hoi. hieu va cac do va ((tinh tai) OR (tinh thai)) cua triet".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((nang xa) or (nang x)) hoi. hieu va cac do va ((tinh tai) OR (tinh thai)) cua triet*.