Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
su triet » su tien, ve triet
tu sach » su sach, te sach, tu cach
ban dan » ban hang, ban hanh, ban quan
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
nang ma » tang ma, sang ma, nang cao
su viet » so viet
va cam » va cham, va cac, va cao
ma hoi » mai hoi, xa hoi, ma hoa
dan vi » doan vi, don vi, dan va
y nang » ky nang, ly nang, v nang

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)) y nang ma hoi. lieu va cam duc ban dan vi ((su triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) y nang ma hoi. lieu va cam duc ban dan vi ((su triet) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) y nang ma hoi. lieu va cam duc ban dan vi ((su triet) or (su viet))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) y nang ma hoi. lieu va cam duc ban dan vi ((su triet) or (su viet))*.