Perhaps you should try some spelling variations:
sua tiet » suat thiet, cua triet, cua thiet
sua tien » su tien, tuan tien, mua thien
hanh dai » hanh tai, hanh dao, vanh dai
dau xuc » dau xac, dau xua, dau nuoc
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
thi van » thi lan, thi hanh, thi nang
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
xuc va » duc va, tuc va, luc va
ma hoi » mai hoi, xa hoi, ma hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ma hoi. ((thien van) OR (thi van)) dau xuc va hanh dai ((sua tien) OR (sua tiet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ma hoi. ((thien van) or (thi van)) dau xuc va hanh dai ((sua tien) OR (sua tiet))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ma hoi. ((thien van) or (thi van)) dau xuc va hanh dai ((sua tien) OR (sua tiet))*.