Perhaps you should try some spelling variations:
qua tham » qua cham, qua than, qua thanh
van hanh » van thanh, ban hanh, van anh
tham xuc » tham nuoc, tham thuc, pham duc
sach vuc » sach duoc, sach nuoc, sach truc
xuc van » duc van, luc van, vuc van
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
mang xa » mang may, dang xay, mang cua
vi su » va su, ve su, oi su
ki su » ky su

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 vuc ((mang xa) or (lang xa)) hoi. hieu qua tham xuc van hanh ((vi su) or (ki su)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vuc ((mang xa) OR (lang xa)) hoi. hieu qua tham xuc van hanh ((vi su) OR (ki su)) viet.
• Adding a wildcard symbol may retrieve word variants: tu sach vuc ((mang xa) or (lang xa)) hoi. hieu qua tham xuc van hanh ((vi su) or (ki su)) viet*.