Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tham hoc » thai hoc, tham hoa, than hoc
dien cuc » dien tu, dieu cua, dien hoc
vien cac » vien bach, vien dai, vien da
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
va danh » va dinh, va dan, va hanh
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: toc sach y nang ma hoi. hieu va tham hoc va danh ((dien cuc) or (vien cac)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ma hoi. hieu va tham hoc va danh ((dien cuc) OR (vien cac)) tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ma hoi. hieu va tham hoc va danh ((dien cuc) or (vien cac)) tre*.