Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
dinh cac » tinh cach, dinh chuc, dinh chau
vu cham » va cham, vu kham, tu cham
dinh cu » dinh cuu, dinh chuc, dinh chau
va danh » va dinh, va dan, va hanh
ve chim » va chim, ve cham, ve chinh
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa

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 y nang ma hoi. hieu ((ve chim) or (vu cham)) duc va danh ((dinh cac) or (dinh cu)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach y nang ma hoi. hieu ((ve chim) OR (vu cham)) duc va danh ((dinh cac) OR (dinh cu)) tren.
• Adding a wildcard symbol may retrieve word variants: doc sach y nang ma hoi. hieu ((ve chim) or (vu cham)) duc va danh ((dinh cac) or (dinh cu)) tren*.