Perhaps you should try some spelling variations:
cam truc » cau truc, nam truc, lam truoc
dua tren » dung tren
nang cac » nang cao, bang cac, hang cac
cac khoa » cac khoan, cac khoi, dac khoa
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te sach
truc va » thuc va, thuc vat, trung va
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
ty nang » ky nang, ty xang, ty hang
cua tre » cuu tre, cua triet, cua thep
ve cam » ve cham, ve cac, va cam
cua te » cua tu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang cac khoa. hieu ve cam truc va thanh vi ((((dua tren) OR (cua te))) OR (cua tre))~.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang cac khoa. hieu ve cam truc va thanh vi ((((dua tren) or (cua te))) or (cua tre))*.