Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
doc sach » hoc sach, toc sach, nuoc sach
lang van » dang van, tang van, hoang van
qua tham » qua cham, qua than, qua thanh
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
vai cua » dai cua, hai cua, lai cua
y lang » o lang, _ lang, tay lang
vi cua » di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach y lang van hoa. hieu qua tham thuc van hanh ((vi cua) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach y lang van hoa. hieu qua tham thuc van hanh ((vi cua) OR (vai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: doc sach y lang van hoa. hieu qua tham thuc van hanh ((vi cua) or (vai cua)) tre*.