Perhaps you should try some spelling variations:
nha thuoc » nha nuoc, nhan thuc, nha hoc
van hanh » van thanh, ban hanh, van anh
thu sach » thuat sach, thuoc sach, thu hoach
nang mai » nang ma, nang tai, lang mai
xuc van » duc van, luc van, vuc van
tu sach » su sach, te sach, tu cach
mai hoi » mai khoi, dai hoi, lai hoi
ve cac » vien cac
y nang » ky nang, ly nang, v nang
vi nha » ve nha, va nha, li nha

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