?? ???? ??????? ??? ????? ??????? ????????? ???? ???? ??? ??????? ????????? ???????? ??? ??????? ?? ?? ????? ???? ???? ????????? ?? ???? ?????? ?? ??????? ????.???? ????? ????? ????? ??? ???????? ?????????? ??????? ???? ???? ????. ??? ??? ???????? ?? ???? ??? ????? ???: ?? ?????? ??? ?? ???? ????Knowledge is gathered from a number of sources.[16][s