Perhaps you should try some spelling variations:
hoang van » hang va
tham thuc » nham thuc, pham thuc, tam thuc
hoc sach » hoc sinh, hoc cac
van xanh » van anh, van hanh, van manh
thuc van » thuc vat, thuc dan, thuc va
lang van » dang van, tang van, giang van
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
hoc anh » hoc nganh, hoc nhanh, ngoc anh
xanh di » danh di, vanh dai, xanh tai
di cua » dai cua, doi cua, de cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc sach) OR (hoc anh)) _ ((lang van) or (hoang van)) hoa. hieu ve tham thuc van xanh di cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (hoc anh)) _ ((lang van) OR (hoang van)) hoa. hieu ve tham thuc van xanh di cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) OR (hoc anh)) _ ((lang van) or (hoang van)) hoa. hieu ve tham thuc van xanh di cua tu".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) OR (hoc anh)) _ ((lang van) or (hoang van)) hoa. hieu ve tham thuc van xanh di cua tu*.