Perhaps you should try some spelling variations:
dang hanh » dang thanh, ban hanh, dang van
thuc dang » thuoc dang, thuc dan, thuc dung
su triet » su viet, su tien, ve triet
hanh tai » thanh tai, hang tai, han tai
sach ky » sac ky, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
va nay » va ngay, va cay
tai su » tai so, tai tu, lai su
va nam » van nam, ha nam

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 ky) or (sach y)) nang xa hoi. hieu ((va nam) OR (va nay)) thuc dang hanh tai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) nang xa hoi. hieu ((va nam) OR (va nay)) thuc dang hanh tai su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sach y)) nang xa hoi. hieu ((va nam) OR (va nay)) thuc dang hanh tai su triet*".