text Jakarta Gramedia 1990 ind x, 84 hlm ilus 21 cm Soemanto Imam Khasani Bibliografi : hlm. 81 Keselamatan kerja 331.259 6 20090227024957.0 YOGYA-02090000035148 Converted from MARCXML to MODS version 3.5 using MARC21slim2MODS3-5.xsl (Revision 1.106 2014/12/19)