Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
cam truc » nam truc, lam truoc, nam truoc
mai hoi » mai khoi, dai hoi, lai hoi
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach 2, sach vay
vi cua » vai 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: te ((sach v) or (sach y)) nang mai hoi. hieu qua ((cam truc) OR (cau truc)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach v) OR (sach y)) nang mai hoi. hieu qua ((cam truc) OR (cau truc)) va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach v) or (sach y)) nang mai hoi. hieu qua ((cam truc) OR (cau truc)) va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach v) or (sach y)) nang mai hoi. hieu qua ((cam truc) OR (cau truc)) va hanh vi cua tre*.