Perhaps you should try some spelling variations:
tay tang » tay lang, tay trung, tay quang
sach tay » xach tay, sach hay, sach nay
su sach » so sach, vu sach
hanh ki » hanh vi, hanh ky, hanh kien
hieu ve » hieu va, hieu van
su viet » so viet
ve cau » ke cau, va cau, ve cac
luc va » tuc va, loc va
ma hoi » mai hoi, xa hoi, me hoi
ki su » ky su

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 tay tang ((ma hoi) or (ma hoa)). hieu ve cau ((luc va) or (duc va)) hanh ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tay tang ((ma hoi) OR (ma hoa)). hieu ve cau ((luc va) OR (duc va)) hanh ki su viet.
• Adding a wildcard symbol may retrieve word variants: su sach tay tang ((ma hoi) or (ma hoa)). hieu ve cau ((luc va) or (duc va)) hanh ki su viet*.