Perhaps you should try some spelling variations:
bach tuoc » sach duoc, sach nuoc
so triet » su triet, so thiet, bo triet
hanh tai » thanh tai, hang tai, han tai
va hanh » van hanh, va thanh, va danh
bac tuc » bac tu, bac thua
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
tai so » tai sao, dai so, tai co

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y ((nang xa) OR (nang ma)) hoi. hieu va ((bac tuc) or (bach tuoc)) va hanh tai so triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (nang ma)) hoi. hieu va ((bac tuc) OR (bach tuoc)) va hanh tai so triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((nang xa) OR (nang ma)) hoi. hieu va ((bac tuc) or (bach tuoc)) va hanh tai so triet".
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang xa) OR (nang ma)) hoi. hieu va ((bac tuc) or (bach tuoc)) va hanh tai so triet*.