Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
van nhan » van phan, van thanh, danh nhan
ban hanh » ban hang
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
va nhan » ca nhan, va phan, va nha
duc ban » duc tan, duc van, dua ban
doi cua » dai cua, hoi cua
do cua » co cua, de cua, dong cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky nang xa hoi. hieu ((va nhan) OR (van nhan)) duc ban hanh ((do cua) or (doi cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky nang xa hoi. hieu ((va nhan) OR (van nhan)) duc ban hanh ((do cua) OR (doi cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ky nang xa hoi. hieu ((va nhan) OR (van nhan)) duc ban hanh ((do cua) or (doi cua)) te".
• Adding a wildcard symbol may retrieve word variants: doc sach ky nang xa hoi. hieu ((va nhan) OR (van nhan)) duc ban hanh ((do cua) or (doi cua)) te*.