Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
cau tren » cu tren, dau tren, ca tren
te sach » toc sach
sach ty » sach y, sach tu, sach thu
xang xa » mang xa, ang xa, dang xay
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va quan » van quan, tac quan, hai quan
quan ve » quan he, quan vi, quan va
ve cac » va cac, vien cac
ve cau » ke cau, va cau, le cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty ((xang xa) OR (lang xa)) hoi. hieu ve cac thuc va quan ve cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((xang xa) OR (lang xa)) hoi. hieu ve cac thuc va quan ve cau tren".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((xang xa) OR (lang xa)) hoi. hieu ve cac thuc va quan ve cau tren*.