Perhaps you should try some spelling variations:
van trieu » tan trieu, van tien, van tren
toc sach » hoc sach, doc sach, thuoc sach
tan hanh » tan thanh, tang hanh, toan hanh
van tieu » van tien, vay tieu, luan tieu
van hieu » cao hieu
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang ma hoi. hieu va cam duc tan hanh vi ((van trieu) or (((van tieu) OR (van hieu))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ma hoi. hieu va cam duc tan hanh vi ((van trieu) OR (((van tieu) OR (van hieu)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ma hoi. hieu va cam duc tan hanh vi ((van trieu) or (((van tieu) OR (van hieu))))".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ma hoi. hieu va cam duc tan hanh vi ((van trieu) or (((van tieu) OR (van hieu))))*.