Perhaps you should try some spelling variations:
tinh sach » tinh cach, tinh mach, sinh sach
sach van » sach han, sach va, bach van
dua tren » dung tren
thu sach » thuat sach, thuoc sach, thu hoach
nang xa » nang x, lang xa, nang ma
va tinh » may tinh
van anh » van thanh, tuan anh, van minh
cuu tre » cua tre, cau tren, cau treo
tu sach » su sach, te sach, tu cach
anh vi » hanh vi, anh va, anh ve

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)) ky nang xa hoi. lieu va tinh sach van anh vi ((cuu tre) or (dua tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang xa hoi. lieu va tinh sach van anh vi ((cuu tre) OR (dua tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky nang xa hoi. lieu va tinh sach van anh vi ((cuu tre) or (dua tren))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky nang xa hoi. lieu va tinh sach van anh vi ((cuu tre) or (dua tren))*.