Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
va hanh » van hanh, va thanh, va danh
tu cham » toc cham, thi cham
ve cham » va cham, ve chat, vu cham
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
xuc va » duc va, tuc va, luc va
vi va » vi van, vai va, vu va
thiet » thieu

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