Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
sach ky » sac ky, sach ty, sach kem
hanh ve » hanh vi, hanh va, hanh kem
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, luc va
ve cau » ke cau, va cau, ve cac

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