Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
chau tren » cau tren, chay tren, dau tren
tang van » dang van, hoang van, trong van
cham tuc » nham thuc, pham thuc, cham soc
hanh hai » thanh hai, nhanh hai, hang hai
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cu tren » tu tren, dua tren
y tang » ky tang, 6 tang, 7 tang

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y tang van hoa. hieu ve ((cham tuc) or (tham thuc)) va hanh hai ((chau tren) OR (cu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y tang van hoa. hieu ve ((cham tuc) OR (tham thuc)) va hanh hai ((chau tren) OR (cu tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y tang van hoa. hieu ve ((cham tuc) or (tham thuc)) va hanh hai ((chau tren) OR (cu tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach y tang van hoa. hieu ve ((cham tuc) or (tham thuc)) va hanh hai ((chau tren) OR (cu tren))*.