Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
lang mai » lang dai, lang hai, lang man
su sach » so sach, vu sach
tinh va » tich va, trinh van, tinh gia
va phan » van phan, va phat, va phap
sach ky » sac ky, sach y, sach ty
ve phan » ke phan, ve phat, vi phan
mai hoi » mai khoi, dai hoi, lai hoi
ky lang » ky nang, ky dang, ky tang
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: su sach ky lang mai hoi. hieu ((ve phan) or (va phan)) duc va ((tinh va) OR (trinh vat)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang mai hoi. hieu ((ve phan) OR (va phan)) duc va ((tinh va) OR (trinh vat)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky lang mai hoi. hieu ((ve phan) or (va phan)) duc va ((tinh va) OR (trinh vat)) cua te".
• Adding a wildcard symbol may retrieve word variants: su sach ky lang mai hoi. hieu ((ve phan) or (va phan)) duc va ((tinh va) OR (trinh vat)) cua te*.