Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
van tuan » van quan, van ban, anh tuan
so sach » so sanh, bo sach, co sach
cam duc » cam xuc, cao duc, pham duc
vai cua » dai cua, hai cua, lai cua
duc van » duc va, duc tan, duc manh
nang co » nang cao, nang doc, nang noi
y nang » ky nang, ly nang, v nang
co hoi » co hoc, co loi
vi cua » di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang co hoi. ((hieu quan) or (hieu qua)) cam duc van tuan ((vi cua) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang co hoi. ((hieu quan) OR (hieu qua)) cam duc van tuan ((vi cua) OR (vai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: so sach y nang co hoi. ((hieu quan) or (hieu qua)) cam duc van tuan ((vi cua) or (vai cua)) tre*.