Perhaps you should try some spelling variations:
duc tien » duc thien, luc tieng, thuc tien
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
tai duc » tai cuc, mai duc, tai du
xuc van » duc van, luc van, vuc van
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
mai hoa » mai khoa, ma hoa, dai hoa
mau hoa » cau hoa, ma hoa, mau ho
ky dang » ky nang, ky danh
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: su sach ky dang ((mau hoa) or (mai hoa)). hieu ((ve cac) or (va cac)) xuc van hanh tai duc tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky dang ((mau hoa) OR (mai hoa)). hieu ((ve cac) OR (va cac)) xuc van hanh tai duc tien.
• Adding a wildcard symbol may retrieve word variants: su sach ky dang ((mau hoa) or (mai hoa)). hieu ((ve cac) or (va cac)) xuc van hanh tai duc tien*.