Perhaps you should try some spelling variations:
duc tien » duc thien, luc tieng, thuc tien
hanh tai » thanh tai, hang tai, han tai
sach ky » sac ky, sach y, sach ty
tai duc » tai cuc, mai duc, tai du
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
mau hoa » cau hoa, mai hoa, mau ho
ky dang » ky nang, ky danh
luc va » duc va, tuc va, loc va
ve cac » vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky dang ((mau hoa) OR (ma hoa)). hieu ((ve cac) or (va cac)) luc va hanh tai duc tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang ((mau hoa) OR (ma hoa)). hieu ((ve cac) OR (va cac)) luc va hanh tai duc tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang ((mau hoa) OR (ma hoa)). hieu ((ve cac) or (va cac)) luc va hanh tai duc tien".
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang ((mau hoa) OR (ma hoa)). hieu ((ve cac) or (va cac)) luc va hanh tai duc tien*.