Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nang tai » hang tai, tang tai, sang tai
tai khoa » da khoa, noi khoa
dang van » hoang van
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
hieu va » lieu va, hieu qua
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
va cam » va cham, va cac, va cao
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ty nang tai khoa. hieu va cam ((xuc van) or (duc van)) ((dang van) OR (hang va)) cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang tai khoa. hieu va cam ((xuc van) OR (duc van)) ((dang van) OR (hang va)) cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty nang tai khoa. hieu va cam ((xuc van) or (duc van)) ((dang van) OR (hang va)) cua tu".
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang tai khoa. hieu va cam ((xuc van) or (duc van)) ((dang van) OR (hang va)) cua tu*.