Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
thuc may » thuc day, truc may, phuc may
tinh dai » trinh dai, tinh da, tinh hai
cau tren » cu tren, dau tren, ca tren
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
dai cau » dat cau, da cau, dai hau

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((sach ky) or (sach ty)) nang xa hoi. hieu ve tham thuc may tinh dai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach ky) OR (sach ty)) nang xa hoi. hieu ve tham thuc may tinh dai cau tren.
• Adding a wildcard symbol may retrieve word variants: thuat ((sach ky) or (sach ty)) nang xa hoi. hieu ve tham thuc may tinh dai cau tren*.