Perhaps you should try some spelling variations:
cach thuc » anh thuc, cac thu
vat luan » vay luan, dat luan, van luan
cau tren » cu tren, dau tren, ca tren
te sach » toc sach
sach ty » sach y, sach tu, sach thu
lang xa » dang xay, lang van
lang ha » long ha
hieu ve » hieu va, hieu van
ve cach » va cach, ve cac, ve canh
luan vi » quan vi, luan va, luan ve
vi cau » va cau, ve cau, di 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 ((lang xa) OR (lang ha)) hoi. hieu ve cach thuc vat luan vi cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((lang xa) OR (lang ha)) hoi. hieu ve cach thuc vat luan vi cau tren".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((lang xa) OR (lang ha)) hoi. hieu ve cach thuc vat luan vi cau tren*.