Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
cam duc » cam xuc, cao duc, pham duc
tu sach » thu sach, su sach, te sach
nang ra » nang ma, lang ra, nang ro
nang ho » nang hoc, nang co, tang ho
hieu ve » hieu va, hieu van
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 y ((nang ho) or (nang ra)) hoi. hieu ve cam duc va hanh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang ho) OR (nang ra)) hoi. hieu ve cam duc va hanh vi ((cua tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang ho) or (nang ra)) hoi. hieu ve cam duc va hanh vi ((cua tre) or (cau tren))*.