Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hanh hai » thanh hai, nhanh hai, hang hai
nam duoc » nam thuoc, da duoc, dat duoc
van hanh » van thanh, ban hanh, van anh
tu sach » su sach, te sach, tu cach
cao duc » dao duc, cao suc, giao duc
hai cua » thai cua, dai cua, hoi cua
ly nang » ky nang, ly hang, ly vang
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cua te » cua tu

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)) ly nang xa hoi. hieu va ((nam duoc) or (cao duc)) van hanh hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ly nang xa hoi. hieu va ((nam duoc) OR (cao duc)) van hanh hai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ly nang xa hoi. hieu va ((nam duoc) or (cao duc)) van hanh hai cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ly nang xa hoi. hieu va ((nam duoc) or (cao duc)) van hanh hai cua te*.