Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thuc va » thuc vat, thuc dan, thuc day
van hac » van hoc, van ha, van hai
van cac » van cau, van bac, dan cac
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cuu tre » cua tre, cau tren, cau treo
va dan » ca dan, va dao, va dau
dan di » danh di, dan da, dan de
di cuu » di cau, di cua, dinh cuu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu hoach) or (thuoc sach)) ky lang xa hoi. thien ((van cac) OR (van hac)) thuc va dan di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu hoach) OR (thuoc sach)) ky lang xa hoi. thien ((van cac) OR (van hac)) thuc va dan di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu hoach) or (thuoc sach)) ky lang xa hoi. thien ((van cac) OR (van hac)) thuc va dan di cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((thu hoach) or (thuoc sach)) ky lang xa hoi. thien ((van cac) OR (van hac)) thuc va dan di cuu tre*.