Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cam thuc » am thuc, nam thuc, cam thu
van tuan » van quan, van ban, anh tuan
thuc van » thuc vat, thuc dan, thuc va
su triet » su viet, su tien, ve triet
duy can » duy van
hieu ve » hieu va, hieu van
ty sang » ty xang, ty hang, duy sang
tuan vi » quan vi, luan vi, quans vi
ma hoi » mai hoi, xa hoi, ma hoa
ve cam » ve cham, ve cac, va cam
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ty sang) or (duy can)) ma hoi. hieu ve cam thuc van tuan vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty sang) OR (duy can)) ma hoi. hieu ve cam thuc van tuan vi su triet.
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty sang) or (duy can)) ma hoi. hieu ve cam thuc van tuan vi su triet*.