000 00285 a2200109 4500
008 190219b xxu||||| |||| 00| 0
100 _aWalch, Paul S.
245 _aLimnological methods /
_cS. Paul Welch
260 _aNew York
_bMcGraw Hill Book Co.
_c1948
300 _a381p.
942 _2ddc
_cBK
999 _c8499
_d8499