Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
ke cau » ket cau
luc va » duc va, tuc va, loc va
vi cuu » vi luu, vinh cuu
ve cau » va cau, ve cac, le cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (thu hoach)) ky dang xa hoi. hieu ((ve cau) OR (ke cau)) luc va hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thu hoach)) ky dang xa hoi. hieu ((ve cau) OR (ke cau)) luc va hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thu hoach)) ky dang xa hoi. hieu ((ve cau) OR (ke cau)) luc va hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thu hoach)) ky dang xa hoi. hieu ((ve cau) OR (ke cau)) luc va hanh vi cuu tre*.