Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
van hanh » van thanh, ban hanh, van anh
tu sach » su sach, te sach, tu cach
va hanh » va thanh, va danh, ban hanh
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
tu nang » tru nang, tu nong, tu nano
cam lo » nam lo, cam ly, cam o
va cua » va chua, via cua, ca cua
ve cam » ve cham, ve cac, va cam

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) or (thu sach)) tu nang xa hoi. hieu ve cam lo ((va hanh) OR (van hanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tu nang xa hoi. hieu ve cam lo ((va hanh) OR (van hanh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) tu nang xa hoi. hieu ve cam lo ((va hanh) OR (van hanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) tu nang xa hoi. hieu ve cam lo ((va hanh) OR (van hanh)) va cua tre*.