Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thuc dan » thuc hanh, hoc dan
dang xay » dang van, van xay
danh tai » doanh tai, dinh tai, hanh tai
tai cua » thai cua, tai cuc, tri cua
thuc va » thuc day
sach ky » sac ky, sach y, sach ty
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
va nam » van nam, ha nam, va nay
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: toc sach ky dang xay hoi. lieu va nam ((((thuc va) OR (thuc vat))) or (thuc dan)) danh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xay hoi. lieu va nam ((((thuc va) OR (thuc vat))) OR (thuc dan)) danh tai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xay hoi. lieu va nam ((((thuc va) OR (thuc vat))) or (thuc dan)) danh tai cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xay hoi. lieu va nam ((((thuc va) OR (thuc vat))) or (thuc dan)) danh tai cua te*.