Perhaps you should try some spelling variations:
thuoc tai » nuoc tai, hoc tai, thuc tap
thanh va » thanh van, hanh va, thanh ha
thuoc ma » hoc ma, duoc ma
vu sach » vu bach, su sach, vu khach
hieu le » hieu ve, hieu he, hieu ly
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
le nam » ly nam, he nam, le na
va cua » va chua, via cua, ca cua
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: vu sach ((ky lang) OR (ky dang)) xa hoi. hieu le nam ((thuoc tai) or (thuoc ma)) thanh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((ky lang) OR (ky dang)) xa hoi. hieu le nam ((thuoc tai) OR (thuoc ma)) thanh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((ky lang) OR (ky dang)) xa hoi. hieu le nam ((thuoc tai) or (thuoc ma)) thanh va cua te".
• Adding a wildcard symbol may retrieve word variants: vu sach ((ky lang) OR (ky dang)) xa hoi. hieu le nam ((thuoc tai) or (thuoc ma)) thanh va cua te*.