Perhaps you should try some spelling variations:
phap thuc » phap thu, phap hoc, phap tu
dan quans » dan quan, dan quang, dang quang
hoc sach » hoc sinh, hoc cac, hoc anh
hoa lang » hoa dan, hoa van
thuc dan » thuc hanh, hoc dan, thuc vat
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu va, hieu van
ve phap » va phap, de phap, ve phan
van hoi » van hoa, van hoc, van hoe
vi cua » di cua
o lang » hoi lang

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 ((o lang) or (hoa lang)) van hoi. hieu ve phap thuc dan quans ((vi cua) OR (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((o lang) OR (hoa lang)) van hoi. hieu ve phap thuc dan quans ((vi cua) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ((o lang) or (hoa lang)) van hoi. hieu ve phap thuc dan quans ((vi cua) OR (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ((o lang) or (hoa lang)) van hoi. hieu ve phap thuc dan quans ((vi cua) OR (vai cua)) tre*.