Perhaps you should try some spelling variations:
thuat san » thuat toan, thuat song, thuat lanh
nam thuoc » nam thuc, nha thuoc, cay thuoc
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
ma hanh » va hanh, da hanh, na hanh
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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 (thuat san)) ky tang xa hoi. hieu van ((nam thuoc) OR (nam thu)) ma hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuat san)) ky tang xa hoi. hieu van ((nam thuoc) OR (nam thu)) ma hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuat san)) ky tang xa hoi. hieu van ((nam thuoc) OR (nam thu)) ma hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuat san)) ky tang xa hoi. hieu van ((nam thuoc) OR (nam thu)) ma hanh vi cua tre*.